Removing solution

ABSTRACT

The present invention provides a resist-removing solution for low-k film and a cleaning solution for via holes or capacitors, the solutions comprising hydrogen fluoride (HF) and at least one member selected from the group consisting of organic acids and organic solvents. The invention also provides a method of removing resist and a method of cleaning via holes or capacitors by the use of the solutions.

TECHNICAL FIELD

The present invention relates to a resist-removing solution for low-kfilm and a cleaning solution for via holes or capacitors.

BACKGROUND ART

In recent years a technology has been developed to use low-k film (lowdielectric constant film), which exhibits a low relative dielectricconstant, in place of SiO₂ film in semiconductor devices. With thistechnological development, it has become necessary to etch low-k film inthe production process of semiconductor devices. Conventionally, afterthe film is subjected to dry etching, O₂ plasma ashing is performed toremove the resist; however, such a treatment may damage low-k film. Itis, therefore, desirable to remove resist with a chemical solution,without O₂ plasma ashing (or after carrying out H₂ plasma ashing orlight O₂ plasma ashing). However, the resist-removing solutions proposedheretofore cannot be used for such a purpose because they fail to removethe resist (for example, KRF (Krypton F) resist) itself formed on low-kfilm while they etch the low-k film.

In the production process of a semiconductor device, after forming viaholes, titanium compounds and/or polymers may remain on the sidewallsand/or the bottoms of the via holes. The development of a composition istherefore desired that can be used to remove such titanium compoundsand/or polymers from via holes.

Furthermore, in the formation of a metal capacitor in the semiconductordevice production process, polymers, resist residue, and titaniumcompounds may remain after the dry etching of an upper or lowerelectrode metal film (TiN, Ti, etc.) of the metal capacitor. Thedevelopment of a composition is therefore desired that can be used toremove such polymers, resist residue, and titanium compounds.

Until recently, semiconductor devices with an Al/SiO₂ multilevelinterconnection structure have mainly been produced, which use aluminum,aluminum alloy or the like as a wiring material, and a SiO₂ film as aninterlayer dielectric. In order to reduce the wiring delay caused by themicrominiaturization of devices, semiconductor devices with a Cu/low-kmultilevel interconnection structure are now being developed, which useCu as a wiring material having low resistance; and low-k film (lowdielectric constant film) as an interlayer dielectric having lowinterconnect capacitance, in place of the SiO₂ film.

In the Al/SiO₂ multilevel interconnection structure, wiring layers andvia layers are separately formed; the wiring layers supplying electriccurrent horizontally to a processed wafer; and the via layers formingthe wiring through vertical holes that connect the wiring layers. Eachwiring layer is formed by producing convex metal wiring (such as Al) bymetal dry etching, and depositing an interlayer dielectric such as SiO₂film to embed the wiring. After the deposition of an interlayerdielectric such as SiO₂ film, the via layer is formed by subjecting theinterlayer dielectric to dry etching to form a hole (via hole), andfilling the hole with a metal such as Al or W.

The Cu/low-k multilevel interconnection structure is produced by aprocess called damascene, wherein the wiring structure is obtained byforming a trench or a hole (via hole) in low-k film by dry etching, andthen filling the trench or hole with a wiring material such as copper.In the method called dual damascene, trenches for wiring and via holesare formed in low-k film at the same time, and then filled with a wiringmaterial such as copper. A dual damascene structure can be formed by avia-first process, wherein the via holes are formed prior to thetrenches for wiring; or conversely, by a trench-first process, whereinthe trenches for wiring are formed prior to the via holes; or by otherprocesses such as a middle-first process or a dual hard mask process. Inthe dual damascene process or the like, a filling material is used inmany cases. In the via-first process, for example, via holes are formedby dry etching and then filled with a filling material, followed bylithography and etching for the formation of trenches. Thereafter thefilling material must be selectively removed.

In the Al/SiO₂ multilevel interconnection structure, the metal etchingfor the formation of wiring uses a gas such as chlorine or hydrogenbromide, and the via etching for the formation of via holes uses a mixedgas of fluorocarbon gas, hydrofluorocarbon gas, an inert gas such as Ar,oxygen, an oxygen-containing gas such as carbon monoxide, etc. Aftermetal etching or the via etching of the interlayer dielectric for viahole formation, ashing is performed using an oxygen-containing plasma toremove unnecessary substances such as resist and etching residues. Theresidue remaining after ashing is removed using a removing solution. Inthe case of metal etching, the residue consists of oxides of aluminum,etc., that contain a small amount of organic substances such as resist.Since this residue is formed on the sidewalls of aluminum wiring, it maybe referred to as “sidewall polymer,” “rabbit ear,” and so on. In thecase of via etching, the residue consists of oxides or fluorides of Ti,TiN, or other metal barrier films that contain a small amount of organicsubstances such as resist and fluorocarbon polymers. This residue mayalso be referred to as “sidewall polymer.” In many cases the residueafter metal or via hole etching is subjected to an ashing treatmentuntil the resist is removed using oxygen plasma, with the result thatthe principal component of the etching residue is an oxide that has beenmade inorganic.

In the Cu/low-k multilevel interconnection structure, by contrast, thedamascene structure of a trench or a via hole in low-k film is formed bydry etching using a fluorocarbon gas mixed with nitrogen, etc. The useof nitrogen in the dry etching gas enhances processing accuracy.However, reaction of the gas with low-k film containing silicon forms aresidue of nonvolatile nitrided silicon. If ashing is completelyperformed using an oxygen-containing plasma to remove the resist andresidue after etching, the low-k film will be damaged, causing a changein dielectric constant. This kind of plasma ashing, therefore, is notperformed in many cases; instead, ashing may be carried out with aplasma of hydrogen, nitrogen, noble gas, a mixture of these gases, orthe like, or light ashing may be carried out with an oxygen-containingplasma. Also, in many cases, to minimize the damage to the low-k film,the resist and filling material are not completely removed by ashing. Ifa nitrogen-containing gas is used for plasma ashing, the residuecontains further nitrided silicon in a large amount. In such a case,even after ashing, a relatively large amount of resist, antireflectioncoating, filling material, and nitrogen-containing etching residue suchas silicone nitride are present. Even if ashing is carried out to aconsiderable extent, it is difficult to remove all of the resist,antireflection coating, and filling material. As a result, the principalcomponent of the residue present after etching in the damascene processis an organic substance that originates in the resist, antireflectioncoating, filling material, and fluorocarbon polymer, and contains aninorganic substance such as silicon nitride.

There have been many patent applications filed for removing solutionsthat can be used to remove the mineralized residue produced by dryetching in the process of forming an Al/SiO₂ multilevel interconnectionstructure; and for cleaning solutions that can be used to clean theformed pattern. Japanese. Unexamined Patent Publication No. 1989-146331discloses a cleaning solution obtained by mixing hydrofluoric acid withan organic solvent such as isopropanol, and mentions that this cleaningsolution enhances wettability and uniformity in cleaning. However, itdoes not refer to the removal of dry etching residue or resist, whichthe present invention deals with. Japanese Patent No. 3255551 disclosesa resist-removing composition that contains at least one anticorrosiveselected from the group consisting of HF, water-soluble organicsolvents, aromatic hydroxy compounds, acetylene alcohols,carboxyl-containing organic compounds and anhydrides thereof, andtriazole compounds. It mentions sulfoxides, amides, polyhydric alcohols,etc., as effective organic solvents. According to Japanese UnexaminedPatent Publication No. 1998-50647, after the formation of a contacthole, the contact hole is cleaned by carefully etching the native oxideat the bottom of the contact hole and the oxide on the sidewalls thereofcontaining pollutants such as etching residues and metal substances. Itdiscloses that when a contact hole formed by penetrating three kinds offilms, i.e., a plasma silicon oxide film, a low-pressure chemical vapordeposition silicon oxide film, and a BPSG film, is cleaned in a mixedsolution of a low concentration (about 0.25% to about 0.5% by weight) ofhydrogen fluoride, isopropanol, and DIW (deionized water), the contacthole obtains an uniform profile without level differences. U.S. Pat. No.6,150,282 discloses the use of hydrogen fluoride and an organic solventfor providing a cleaning solution and a cleaning method for etchingresidue after the formation of a via hole in a silicon oxide film. Itdiscloses a method of removing and etching at least one of a mask, anetching residue, a silicon oxide film, and a silicon nitride film, usinga removing solution containing hydrogen fluoride, an organic solvent,and water. Japanese Unexamined Patent Publication No. 1999-340183discloses a cleaning solution containing 20% or less by weight ofhydrogen fluoride, an alcohol with a dielectric constant of 10 or more,etc., which can be used for cleaning after via hole etching or forremoving sidewall polymers after the dry etching of metal wiring whileinhibiting the corrosion of the metal wiring of aluminum, etc.

The above inventions, however, do not consider the use of low-k film asan interlayer dielectric, and copper as a wiring material. They areintended to remove inorganic residue after dry etching or to clean theformed pattern, in the formation of an Al/SiO₂ multilevelinterconnection structure.

A principal object of the present invention is to provide aresist-removing solution for low-k film, a cleaning solution for viaholes, and a cleaning solution for metal capacitors.

DISCLOSURE OF THE INVENTION

The present invention is aimed at removing or stripping resist,antireflection coatings, filling materials, and etching residuesincluding these, after dry etching for the formation of a Cu/low-kmultilevel interconnection structure. The object to be removed in thepresent invention differs from that in the case of the Al/SiO₂multilevel interconnection structure. When using low-k film as aninterlayer dielectric, the etching residue contains a high proportion oforganic substances such as resist, an antireflection coating, and afilling material, and also contains the residue of nitrided silicon suchas SiN. In order to remove such residue, a removing solution thatcontains a large amount of organic compounds and that selectivelydissolves silicon nitrides is required. The present inventors haveconfirmed that the effect of selectively dissolving silicon nitrides inthe removing solution can be evaluated based on the effect ofselectively etching silicon nitride (SiN) films. That is, a removingsolution that is more capable of selectively etching silicon nitride(SiN) films, can better dissolve silicon nitrides in etching residue,thus removing the residue more effectively. Moreover, copper is used asa wiring material in low-k film. Therefore, the removing solution mustnot etch copper. No removing solutions have ever been developed thatmeet these demands.

The removing solution of the present invention comprises a mixedsolution of hydrogen fluoride, an organic acid and/or an organicsolvent, and is capable of controlling the etching of wiring metals suchas copper, insulating film barriers, low-k film, and etching residue.Specifically, the removing solution of the invention has the followingfeatures:

(1) it inhibits the corrosion of metals such as copper;

(2) it selectively etches insulating film barriers to separate etchingresidue from the insulating film barriers or low-k film;

(3) it selectively dissolves silicon nitride (SiN), etc., contained inetching residue; and

(4) with an organic solvent it dissolves organic components in etchingresidue.

These features allow the etching solution of the present invention toremove etching residue.

In the present invention, for example, a removing solution composed ofhydrogen fluoride, isopropanol, and water shows its greatest effectswhen the weight ratio of hydrogen fluoride/isopropanol/water is in therange of 1.00-5.00 mass %/87.00-98.5 mass %/0.50-8.00 mass %.

There have been many patent applications filed for cleaning solutionsand removing solutions containing hydrogen fluoride, an organic solventsuch as isopropanol, and water. The solutions disclosed in theseapplications are not used to form a Cu/low-k multilevel interconnectionstructure, but to form an Al/SiO₂ multilevel interconnection structure;and they are intended to remove different objects from that of thepresent invention. Such solutions are described below.

Japanese Unexamined Patent Publications No. 1989-146331 and No.1998-50647 disclose similar cleaning solutions of hydrogen fluoride,isopropanol, and water. In these, however, the hydrogen fluorideconcentration is 0.5% or less by weight, and they cannot selectivelyetch an insulating film barrier nor a silicon nitride (SiN) film, sothat they have a poor ability to remove resist, antireflection coatings,filling materials, and etching residue. In particular, the invention ofJapanese Unexamined Patent Publication No. 1998-50647 is intended toprovide a uniform profile without level differences when cleaning acontact hole, and it is characterized by almost the same etching speedsfor the plasma silicon oxide film, low-pressure chemical vapordeposition silicon oxide film, and BPSG film that are used in theinvention.

In clear contrast to this, the present invention is characterized byselectively etching an insulating film barrier and a silicon nitride(SiN) film over low-k film. When the removing solution of the presentinvention is used to etch a plasma silicon oxide film, a low-pressurechemical vapor deposition silicon oxide film, and a BPSG film, anextremely large amount of the BPSG film is etched in the same manner assilicon nitride is etched.

According to Japanese Patent No. 3255551, effective organic solvents aresulfoxides, amides, polyhydric alcohols, etc. However, polyhydricalcohols do not have much effect on selectively etching silicon nitride(SiN) over low-k film. Sulfoxides and amides tend to heavily corrodecopper, and particularly dimethyl sulfoxide, which is used in theexamples, causes extremely heavy corrosion of copper. From the use ofanticorrosives, it is obvious that copper is not intended as a wiringmaterial. In the present invention, by contrast, an organic solvent thatdoes not need any anticorrosives is used. The removing solution ofJapanese Patent No. 3255551 is not used to form a Cu/low-k multilevelinterconnection structure.

The composition of U.S. Pat. No. 6,150,282 contains substantially nowater, thus causing little metal corrosion. In the present invention, bycontrast, when silicon nitride (SiN) is contained in etching residue,water is required. This is because without water, silicon nitride (SiN)cannot be selectively removed over low-k film. Moreover, the organicsolvents used in the present invention cause little corrosion of coppereven when the amount of water is not minimized. Isopropanol, which waspreviously mentioned, is one example of such organic solvents. In U.S.Pat. No. 6,150,282, the amount of water must be reduced in order toprevent the corrosion of the metals used for the formation of an Al/SiO₂multilevel interconnection structure, such as aluminum. Obviously, thecomposition of U.S. Pat. No. 6,150,282 is not intended as a removingsolution for forming a Cu/low-k multilevel interconnection structure.

U.S. Pat. No. 6,150,282 discloses the use of oxolanes, sulfolanes,esters, ketones, aldehydes, lactones, halogenated hydrocarbons,alcohols, amines, imides, etc., as organic solvents. However, it doesnot disclose the use of water-soluble organic solvents, which isimportant for a removing solution used for forming a Cu/low-k multilevelinterconnection structure. In the case of a water-soluble organicsolvent, the removing solution remaining on the substance that has beentreated with the solution can be removed by simply using pure waterwithout intermediate rinsing. When the removing solution of the presentinvention removes resist, antireflection coatings, filling materials,and etching residues including these, it also slightly and uniformlyetches the insulating film barriers and low-k film that are in contactwith them. In this case, when the organic solvent is water-insoluble,the surface of an insulating film barrier or low-k film becomes rough,resulting in an undesirable form after removal treatment. It is thusdesirable that the organic solvent used in a removing solution forforming a Cu/low-k multilevel interconnection structure bewater-soluble. However, this is not disclosed in U.S. Pat. No.6,150,282. For these reasons, halogenated hydrocarbons, which arenonaqueous solvents; and water-insoluble oxolanes, sulfolanes, esters,ketones, aldehydes, lactones, alcohols, amines, and imides, aredifficult to use in a removing solution for the formation of a Cu/low-kmultilevel interconnection structure.

The use of sulfolanes, amines, and imides causes copper corrosion. Whenalcohols are used, although alcohols having one OH group are consideredto be desirable, methanol corrodes copper. Ethanol corrodes copper moreheavily than isopropanol does. In the present invention, methanol andethanol are not used singly, but they can be used in combination withother organic solvents.

On the other hand, water-soluble alcohols having three or more carbonatoms, such as propanol and t-butanol, cause little corrosion of copper,and allow the removal of the remaining removing solution after theremoval treatment, simply by rinsing with pure water, thus achieving anefficient removal treatment with a small number of steps. The presentinventors found that water-soluble alcohols having three or more carbonatoms, such as propanol and t-butanol, are useful for forming Cu/low-kmultilevel interconnection structures. U.S. Pat. No. 6,150,282 does notmention such a fact, and includes many removing solutions that areunsuitable for forming Cu/low-k multilevel interconnection structures.The present invention also discloses that preferable esters and ketonesare water-soluble, and that methyl acetate, ethyl acetate, butylacetate, acetone, etc. are highly effective in selectively etchingsilicon nitride (SiN) over low-k film, and are therefore the mostsuitable esters and ketones for effectively removing resist,antireflection coatings, and etching residues including these forforming a Cu/low-k multilevel interconnection structure. U.S. Pat. No.6,150,282, however, does not mention any specific organic solvents thatare useful in a removing solution for forming a Cu/low-k multilevelinterconnection structure.

The invention of Japanese Unexamined Patent Publication No. 1998-340183is characterized by using a cleaning solution containing 20% or less byweight of hydrogen fluoride, an alcohol (R—OH) with a dielectricconstant of 10 or more, etc., to provide a sidewall polymer removingsolution that causes little metal corrosion. Based onR—OH+2HF->(R—OH)H⁺+HF₂ ⁻, HF is slightly dissociated, generating a smallamount of HF₂ ⁻ ions. The resulting small amount of HF₂ ⁻ ions functionto remove sidewall polymers and inhibit a reaction with aluminum. In thepresent invention, by contrast, an organic solvent such as an alcoholdissociates a hydrogen bond polymer (HF)_(n), allowing HF and the protonH⁺ supplied from HF and (HF)_(n) (wherein n is 2 or more) to selectivelyetch an insulating film barrier and a silicon nitride (SiN) film overlow-k film, thus removing etching residue.

Japanese Unexamined Patent Publication No. 1999-340183 disclosesmethanol as an organic solvent that is effective as a sidewall polymerremoving solution in its examples. In many cases, the sidewall polymerproduced in the formation of aluminum wiring in an Al/SiO₂ multilevelinterconnection structure is made inorganic by ashing. The speed ofetching an alumina film (Al₂O₃ film) can be used as an index for theremoval of this polymer. The faster this film is etched, the more easilythe sidewall polymer can be removed. As shown in the examples, whenmethanol is used, the Al₂O₃ etching speed is higher, and the effect ofremoving the sidewall polymer of aluminium wiring is greater, than whenisopropanol is used. The silicon nitride (SiN) film can be moreselectively etched with methanol than with isopropanol. However, copperis much more heavily corroded with methanol than with isopropanol.

Japanese Unexamined Patent Publication No. 1999-340183 does not disclosethat other solvents such as isopropanol are effective for inhibitingcopper corrosion. The resist, antireflection coating, etching residuesincluding these, etc., removed in the formation of the Cu/low-kmultilevel interconnection structure contains organic substances in alarge amount. Furthermore, Japanese Unexamined Patent Publication No.1999-340183 does not disclose that these organic substances can be moreeasily dissolved and removed, using isopropanol rather than methanol.These indicate that Japanese Unexamined Patent Publication No.1999-340183 does not provide a removing solution used for the formationof a Cu/low-k multilevel interconnection structure.

In a removing solution comprising hydrogen fluoride, an organic solvent,and water, the present invention uses an organic acid and/or an organicsolvent (such as isopropanol and acetic acid) that cause littlecorrosion of copper and that selectively etch a silicon nitride (SiN)film over low-k film, thus providing a useful removing solution for theformation of a Cu/low-k multilevel interconnection structure.

The present invention relates to the following removing solutions andremoving methods, cleaning solutions and cleaning methods, etc.

Item 1: A resist-removing solution for low-k film comprising hydrogenfluoride (HF) and at least one member selected from the group consistingof organic acids and organic solvents.

Item 2: A resist-removing solution according to item 1, furthercomprising at least one member selected from the group consisting ofammonia and amines.

Item 3: A removing solution according to item 1, wherein the solution isused for ultrasonic cleaning.

Item 4: A removing solution according to item 1, wherein the low-k filmhas a dielectric constant greater than 1 but not greater than 3.

Item 5: A removing solution according to item 1, whereby a SiN film canbe etched to a depth of at least 1 Å.

Item 6: A removing solution according to item 1, wherein the organicacids or organic solvents have an SP value of 7 to 17.

Item 7: A removing solution according to item 1, wherein theconcentration of HF is in the range of 0.01 to 10 mass %.

Item 8: A removing solution according to item 1, wherein said at leastone member selected from the group consisting of organic acids andorganic solvents is organic acid(s) or a mixture of organic acid(s) andorganic solvent(s); and the concentration of HF is in the range of 0.01to 5 mass %.

Item 9: A removing solution according to item 1, wherein said at leastone member selected from the group consisting of organic acids andorganic solvents is organic solvent(s); and the concentration of HF isin the range of 0.01 to 10 mass %.

Item 10: A removing solution according to item 1, further comprisingwater, wherein the weight ratio of HF/organic acid/water is in the rangeof 0.01 to 5 mass %/49 to 99.9 mass %/0 to 50 mass %; and the organicacid is at least one member selected from the group consisting ofmonocarboxylic acids, sulfonic acids, and polycarboxylic acids.

Item 11: A removing solution according to item 10, wherein themonocarboxylic acids are at least one member selected from the groupconsisting of acetic acid, propionic acid, butyric acid, isobutyricacid, valeric acid, caproic acid, caprylic acid, monochloroacetic acid,dichloroacetic acid, trichloroacetic acid, monofluoroacetic acid,difluoroacetic acid, trifluoroacetic acid, α-chlorobutyric acid,β-chlorobutyric acid, γ-chlorobutyric acid, lactic acid, glycolic acid,pyruvic acid, glyoxalic acid, methacrylic acid, and acrylic acid;

the sulfonic acids are at least one member selected from the groupconsisting of methanesulfonic acid, benzenesulfonic acid,trifluoromethanesulfonic acid, and toluenesulfonic acid; and

the polycarboxylic acids are at least one member selected from the groupconsisting of oxalic acid, succinic acid, adipic acid, tartaric acid,and citric acid.

Item 12: A removing solution according to item 9, further comprisingwater, wherein the weight ratio of HF/organic solvent/water is in therange of 0.01 to 10 mass %/49 to 99.9 mass %/0 to 50 mass %; and theorganic solvent is at least one member selected from the groupconsisting of monohydric alcohols, polyols, ketones, amides, nitrites,aldehydes, alkylene glycol monoalkyl ethers, ethers, esters,hydrocarbons, halogen compounds, fluorinated alcohols, phosphate esters,and nitrogen-containing compounds.

Item 13: A removing solution according to item 2, wherein the weightratio of HF/said at least one member selected from the group consistingof ammonia and amines/organic solvents/water is in the range of 0.01 to10 mass %/0.01 to 30 mass %/49 to 99.9 mass %/0 to 50 mass %; and theorganic solvent is at least one member selected from the groupconsisting of monohydric alcohols, polyols, ketones, amides, nitriles,aldehydes, alkylene glycol monoalkyl ethers, ethers, esters,hydrocarbons, halogen compounds, fluorinated alcohols, phosphate esters,and nitrogen-containing compounds.

Item 14: A removing solution according to item 12, wherein themonohydric alcohols are at least one member selected from the groupconsisting of methanol, ethanol, isopropanol (IPA), 1-propanol,1-butanol, 2-butanol, t-butanol, 2-methyl-1-propanol, 1-pentanol,1-hexanol, 1-heptanol, 4-heptanol, 1-octanol, 1-nonyl alcohol,1-decanol, 1-dodecanol, lauryl alcohol, and cyclohexanol, with theproviso that methanol and ethanol are used in combination with otherorganic solvent(s) or organic acid(s);

the polyols are at least one member selected from the group consistingof ethylene glycol, diethylene glycol, 1,2-propanediol, propyleneglycol, 2,3-butanediol, and glycerin;

the ketones are at least one member selected from the group consistingof acetone, acetylacetone, methyl ethyl ketone, methyl isobutyl ketone,cyclohexanone, diethyl ketone, and diisobutyl ketone;

the amides are at least one member selected from the group consisting ofN-methylformamide, N,N-dimethylformamide, N-methylacetamide, andN,N-dimethylacetamide;

the nitriles are at least one member selected from the group consistingof acetonitrile, propionitrile, butyronitrile, isobutyronitrile, andbenzonitrile;

the aldehydes are at least one member selected from the group consistingof formaldehyde, acetaldehyde, and propionaldehyde;

the alkylene glycol monoalkyl ethers are at least one member selectedfrom the group consisting of ethylene glycol monomethyl ether andethylene glycol monoethyl ether;

the ethers are at least one member selected from the group consisting oftetrahydrofuran, dioxane, diisopropyl ether, dibutyl ether,tetrahydropyran, anisole, 1,2-dimethoxyethane, and diethylene glycoldimethyl ether;

the esters are at least one member selected from the group consisting ofmethyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butylacetate, isobutyl acetate, pentyl acetate, hexyl acetate, methylpropionate, ethyl propionate, propyl propionate, isopropyl propionate,butyl propionate, isobutyl propionate, pentyl propionate, hexylpropionate, methyl butyrate, ethyl butyrate, propyl butyrate, isopropylbutyrate, butyl butyrate, isobutyl butyrate, pentyl butyrate, hexylbutyrate, methyl isobutyrate, ethyl isobutyrate, propyl isobutyrate,isopropyl isobutyrate, butyl isobutyrate, isobutyl isobutyrate, pentylisobutyrate, hexyl isobutyrate, methyl valerate, ethyl valerate, propylvalerate, isopropyl valerate, butyl valerate, isobutyl valerate, pentylvalerate, hexyl valerate, methyl isovalerate, ethyl isovalerate, propylisovalerate, isopropyl isovalerate, butyl isovalerate, isobutylisovalerate, pentyl isovalerate, hexyl isovalerate, methyl caproate,ethyl caproate, propyl caproate, isopropyl caproate, butyl caproate,isobutyl caproate, pentyl caproate, hexyl caproate, methyl caprylate,ethyl caprylate, propyl caprylate, isopropyl caprylate, butyl caprylate,isobutyl caprylate, pentyl caprylate, hexyl caprylate, methyl octanoate,ethyl octanoate, propyl octanoate, isopropyl octanoate, butyl octanoate,isobutyl octanoate, pentyl octanoate, hexyl octanoate, methyl nonanoate,ethyl nonanoate, propyl nonanoate, isopropyl nonanoate, butyl nonanoate,isobutyl nonanoate, pentyl nonanoate, hexyl nonanoate, methyl decanoate,ethyl decanoate, propyl decanoate, isopropyl decanoate, butyl decanoate,isobutyl decanoate, pentyl decanoate, hexyl decanoate, methyldodecanoate, ethyl dodecanoate, propyl dodecanoate, isopropyldodecanoate, butyl dodecanoate, isobutyl dodecanoate, pentyldodecanoate, hexyl dodecanoate, methyl laurate, ethyl laurate, propyllaurate, isopropyl laurate, butyl laurate, isobutyl laurate, pentyllaurate, hexyl laurate, methyl acrylate, ethyl acrylate, propylacrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, pentylacrylate, hexyl acrylate, monomethyl oxalate, dimethyl oxalate,monoethyl oxalate, diethyl oxalate, monopropyl oxalate, dipropyloxalate, monobutyl oxalate, dibutyl oxalate, monomethyl succinate,dimethyl succinate, monoethyl succinate, diethyl succinate, monopropylsuccinate, dipropyl succinate, monobutyl succinate, dibutyl succinate,monomethyl adipate, dimethyl adipate, monoethyl adipate, diethyladipate, monopropyl adipate, dipropyl adipate, monobutyl adipate,dibutyl adipate, monomethyl tartrate, dimethyl tartrate, monoethyltartrate, diethyl tartrate, monopropyl tartrate, dipropyl tartrate,monobutyl tartrate, dibutyl tartrate, monomethyl citrate, dimethylcitrate, monoethyl citrate, diethyl citrate, monopropyl citrate,dipropyl citrate, monobutyl citrate, dibutyl citrate, dimethylphthalate, diethyl phthalate, dipropyl phthalate, dibutyl phthalate,dipentyl phthalate, dihexyl phthalate, diheptyl phthalate, dioctylphthalate, dinonyl phthalate, didecyl phthalate, didodecyl phthalate,dimethyl terephthalate, diethyl terephthalate, dipropyl terephthalate,dibutyl terephthalate, dipentyl terephthalate, dihexyl terephthalate,diheptyl terephthalate, dioctyl terephthalate, dinonyl terephthalate,didecyl terephthalate, didodecyl terephthalate, propylene carbonate, andγ-butyrolactone;

the hydrocarbons are at least one member selected from the groupconsisting of hexane, cyclohexane, octane, isooctane, benzene, andtoluene;

the halogen compounds are at least one member selected from the groupconsisting of chloroform, o-dichlorobenzene, perfluorohexane, andperfluoromethylcyclohexane;

the fluorinated alcohols are at least one member selected from the groupconsisting of trifluoroethanol, pentafluoropropanol, and2,2,3,3-tetrafluoropropanol;

the phosphate esters are at least one member selected from the groupconsisting of dimethyl phosphate, dibutyl phosphate, diphenyl phosphate,dibenzyl phosphate, trimethyl phosphate, triethyl phosphate, tripropylphosphate, tributyl phosphate, and triphenyl phosphate; and

the nitrogen-containing compounds are at least one member selected fromthe group consisting of tetramethylurea and N-methyl-2-pyrrolidone.

Item 15: A method of removing resist, comprising treating an objecthaving resist on the surface of a low-k film or on an antireflectioncoating (BARC) over a low-k film, by the use of the removing solution ofitem 1 under temperature and time conditions such that the resist can beremoved without substantially damaging the low-k film.

Item 16: A method according to item 15, comprising an ashing treatmentfor the resist without substantially damaging the low-k film, beforetreating the object using the removing solution.

Item 17: A method according to item 15, wherein the low-k film issubstantially undamaged because the low-k film is substantially unetchedand/or the dielectric constant of the low-k film is substantiallyunchanged before and after the treatment.

Item 18: A method according to item 15, comprising treating the objectwhile performing ultrasonic cleaning.

Item 19: A resist-removed object that can be obtained according to themethod of item 15.

Item 20: A cleaning solution for a via hole or a capacitor comprisinghydrogen fluoride (HF) and at least one member selected from the groupconsisting of organic acids and organic solvents.

Item 21: A cleaning solution according to item 20, further comprising atleast one member selected from the group consisting of ammonia andamines.

Item 22: A removing solution according to item 20, wherein the solutionis used for ultrasonic cleaning.

Item 23: A cleaning solution according to item 20, whereby a TiN filmcan be etched to a depth of at least 0.01 Å.

Item 24: A cleaning solution according to item 20, further comprisingwater, wherein the weight ratio of HF/organic acid/water is in the rangeof 0.01 to 5 mass % 49 to 99.9 mass %/0 to 50 mass %; and the organicacid is at least one member selected from the group consisting ofmonocarboxylic acids, sulfonic acids, and polycarboxylic acids.

Item 25: A cleaning solution according to item 24, wherein themonocarboxylic acids are at least one member selected from the groupconsisting of acetic acid, propionic acid, butyric acid, isobutyricacid, valeric acid, caproic acid, caprylic acid, monochloroacetic acid,dichloroacetic acid, trichloroacetic acid, monofluoroacetic acid,difluoroacetic acid, trifluoroacetic acid, α-chlorobutyric acid,β-chlorobutyric acid, γ-chlorobutyric acid, lactic acid, glycolic acid,pyruvic acid, glyoxalic acid, methacrylic acid, and acrylic acid;

the sulfonic acids are at least one member selected from the groupconsisting of methanesulfonic acid, benzenesulfonic acid,trifluoromethanesulfonic acid, and toluenesulfonic acid; and

the polycarboxylic acids are at least one member selected from the groupconsisting of oxalic acid, succinic acid, adipic acid, tartaric acid,and citric acid.

Item 26: A cleaning solution according to item 20, further comprisingwater, wherein the weight ratio of HF/organic solvent/water is in therange of 0.01 to 10 mass %/49 to 99.9 mass %/0 to 50 mass %; and theorganic solvent is at least one member selected from the groupconsisting of monohydric alcohols, polyols, ketones, amides, nitriles,aldehydes, alkylene glycol monoalkyl ethers, ethers, esters,hydrocarbons, halogen compounds, fluorinated alcohols, phosphate esters,and nitrogen-containing compounds.

Item 27: A cleaning solution according to item 21, wherein the weightratio of HF/said at least one member selected from the group consistingof ammonia and amines/organic solvent/water is in the range of 0.01 to10 mass %/0.01 to 30 mass %/49 to 99.9 mass %/0 to 50 mass %; and theorganic solvent is at least one member selected from the groupconsisting of monohydric alcohols, polyols, ketones, amides, nitriles,aldehydes, alkylene glycol monoalkyl ethers, ethers, esters,hydrocarbons, halogen compounds, fluorinated alcohols, phosphate esters,and nitrogen-containing compounds.

Item 28: A cleaning solution according to item 26, wherein themonohydric alcohols are at least one member selected from the groupconsisting of methanol, ethanol, isopropanol (IPA), 1-propanol,1-butanol, 2-butanol, t-butanol, 2-methyl-1-propanol, 1-pentanol,1-hexanol, 1-heptanol, 4-heptanol, 1-octanol, 1-nonyl alcohol,1-decanol, 1-dodecanol, lauryl alcohol, and cyclohexanol;

the polyols are at least one member selected from the group consistingof ethylene glycol, diethylene glycol, 1,2-propanediol, propyleneglycol, 2,3-butanediol, and glycerin;

the ketones are at least one member selected from the group consistingof acetone, acetylacetone, methyl ethyl ketone, methyl isobutyl ketone,cyclohexanone, diethyl ketone, and diisobutyl ketone;

the amides are at least one member selected from the group consisting ofN-methylformamide, N,N-dimethylformamide, N-methylacetamide, andN,N-dimethylacetamide;

the nitriles are at least one member selected from the group consistingof acetonitrile, propionitrile, butyronitrile, isobutyronitrile, andbenzonitrile;

the aldehydes are at least one member selected from the group consistingof formaldehyde, acetaldehyde, and propionaldehyde;

the alkylene glycol monoalkyl ethers are at least one member selectedfrom the group consisting of ethylene glycol monomethyl ether andethylene glycol monoethyl ether;

the ethers are at least one member selected from the group consisting oftetrahydrofuran, dioxane, diisopropyl ether, dibutyl ether,tetrahydropyran, anisole, 1,2-dimethoxyethane, and diethylene glycoldimethyl ether;

the esters are at least one member selected from the group consisting ofmethyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butylacetate, isobutyl acetate, pentyl acetate, hexyl acetate, methylpropionate, ethyl propionate, propyl propionate, isopropyl propionate,butyl propionate, isobutyl propionate, pentyl propionate, hexylpropionate, methyl butyrate, ethyl butyrate, propyl butyrate, isopropylbutyrate, butyl butyrate, isobutyl butyrate, pentyl butyrate, hexylbutyrate, methyl isobutyrate, ethyl isobutyrate, propyl isobutyrate,isopropyl isobutyrate, butyl isobutyrate, isobutyl isobutyrate, pentylisobutyrate, hexyl isobutyrate, methyl valerate, ethyl valerate, propylvalerate, isopropyl valerate, butyl valerate, isobutyl valerate, pentylvalerate, hexyl valerate, methyl isovalerate, ethyl isovalerate, propylisovalerate, isopropyl isovalerate, butyl isovalerate, isobutylisovalerate, pentyl isovalerate, hexyl isovalerate, methyl caproate,ethyl caproate, propyl caproate, isopropyl caproate, butyl caproate,isobutyl caproate, pentyl caproate, hexyl caproate, methyl caprylate,ethyl caprylate, propyl caprylate, isopropyl caprylate, butyl caprylate,isobutyl caprylate, pentyl caprylate, hexyl caprylate, methyl octanoate,ethyl octanoate, propyl octanoate, isopropyl octanoate, butyl octanoate,isobutyl octanoate, pentyl octanoate, hexyl octanoate, methyl nonanoate,ethyl nonanoate, propyl nonanoate, isopropyl nonanoate, butyl nonanoate,isobutyl nonanoate, pentyl nonanoate, hexyl nonanoate, methyl decanoate,ethyl decanoate, propyl decanoate, isopropyl decanoate, butyl decanoate,isobutyl decanoate, pentyl decanoate, hexyl decanoate, methyldodecanoate, ethyl dodecanoate, propyl dodecanoate, isopropyldodecanoate, butyl dodecanoate, isobutyl dodecanoate, pentyldodecanoate, hexyl dodecanoate, methyl laurate, ethyl laurate, propyllaurate, isopropyl laurate, butyl laurate, isobutyl laurate, pentyllaurate, hexyl laurate, methyl acrylate, ethyl acrylate, propylacrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, pentylacrylate, hexyl acrylate, monomethyl oxalate, dimethyl oxalate,monoethyl oxalate, diethyl oxalate, monopropyl oxalate, dipropyloxalate, monobutyl oxalate, dibutyl oxalate, monomethyl succinate,dimethyl succinate, monoethyl succinate, diethyl succinate, monopropylsuccinate, dipropyl succinate, monobutyl succinate, dibutyl succinate,monomethyl adipate, dimethyl adipate, monoethyl adipate, diethyladipate, monopropyl adipate, dipropyl adipate, monobutyl adipate,dibutyl adipate, monomethyl tartrate, dimethyl tartrate, monoethyltartrate, diethyl tartrate, monopropyl tartrate, dipropyl tartrate,monobutyl tartrate, dibutyl tartrate, monomethyl citrate, dimethylcitrate, monoethyl citrate, diethyl citrate, monopropyl citrate,dipropyl citrate, monobutyl citrate, dibutyl citrate, dimethylphthalate, diethyl phthalate, dipropyl phthalate, dibutyl phthalate,dipentyl phthalate, dihexyl phthalate, diheptyl phthalate, dioctylphthalate, dinonyl phthalate, didecyl phthalate, didodecyl phthalate,dimethyl terephthalate, diethyl terephthalate, dipropyl terephthalate,dibutyl terephthalate, dipentyl terephthalate, dihexyl terephthalate,diheptyl terephthalate, dioctyl terephthalate, dinonyl terephthalate,didecyl terephthalate, didodecyl terephthalate, propylene carbonate, andγ-butyrolactone;

the hydrocarbons are at least one member selected from the groupconsisting of hexane, cyclohexane, octane, isooctane, benzene, andtoluene;

the halogen compounds are at least one member selected from the groupconsisting of chloroform, o-dichlorobenzene, perfluorohexane, andperfluoromethylcyclohexane;

the fluorinated alcohols are at least one member selected from the groupconsisting of trifluoroethanol, pentafluoropropanol, and2,2,3,3-tetrafluoropropanol;

the phosphate esters are at least one member selected from the groupconsisting of dimethyl phosphate, dibutyl phosphate, diphenyl phosphate,dibenzyl phosphate, trimethyl phosphate, triethyl phosphate, tripropylphosphate, tributyl phosphate, and triphenyl phosphate; and

the nitrogen-containing compounds are at least one member selected fromthe group consisting of tetramethylurea and N-methyl-2-pyrrolidone.

Item 29: A method of cleaning a via hole, comprising cleaning an objectthat has a via hole, with at least one member selected from the groupconsisting of titanium compounds and polymers adhering to at least onemember selected from the group consisting of the sidewall and the bottomof the via hole, by the use of the cleaning solution of item 20.

Item 30: A method according to item 29, comprising treating the objectwhile performing ultrasonic cleaning.

Item 31: A cleaned object that can be obtained according to the methodof item 29.

Item 32: A method of cleaning a capacitor, comprising cleaning an objectthat has a metal capacitor upper electrode or lower electrode, with atleast one member selected from the group consisting of resist residue,polymers, and titanium compounds adhering to at least one memberselected from the group consisting of the sidewall, the bottom, and thesurface of the electrode, by the use of the cleaning solution of item20.

Item 33: A method according to item 32, comprising treating the objectwhile performing ultrasonic cleaning.

Item 34: A cleaned object that can be obtained according to the methodof item 32.

Item 35: A resist-removing solution according to item 1, wherein thesolution etches, in a treatment time of 0.1 to 120 minutes, (1) aninsulating film barrier to a depth of 1 to 200 Å, (2) low-k film to adepth of 1 to 200 Å, and (3) Cu at an etching rate of no more than 5Å/min; and the solution removes resist, antireflection coating, fillingmaterial, and etching residue including these, after dry etching in theformation of damascene and dual damascene structures for Cu/low-kmultilevel interconnection.

Item 36: A removing solution according to item 35, wherein theinsulating film barrier and the low-k film are Si-containing compoundssuch as SiN, SiC, SiCN, SiOC, and SiO₂.

Item 37: A removing solution according to item 35, wherein the solutionremoves resist, antireflection coating, filling material, and etchingresidue including these after etching with a nitrogen-containing gas oran etching gas mixed with nitrogen, regardless of whether plasma ashingis conducted or not.

Item 38: A removing solution according to item 35, wherein the solutionremoves resist, antireflection coating, filling material, and etchingresidue including these after ashing with a nitrogen-containing gas oran etching gas mixed with nitrogen.

Item 39: A removing solution according to item 35, wherein one or moreinert gases are dissolved in the solution such that the oxygen partialpressure in the solution is below the oxygen partial pressure inair-saturated solution.

Item 40: A removing solution according to item 35, comprising (i) HF,(ii) a protogenic solvent, and (iii) at least one organic compoundselected from the group consisting of polar aprotic solvents having adonor number of no more than 24 and neutral solvents; wherein the weightratio of (i) HF (hydrogen fluoride)/(ii) protogenic solvent/(iii) saidat least one organic compound selected from the group consisting ofpolar aprotic solvents having a donor number of no more than 24 andneutral solvents is in the range of (i) 0.05 to 5 mass %/(ii) 1 to 98.95mass %/(iii) 1 to 98.95 mass %.

Item 41: A removing solution according to item 35, comprising (i) HF,(ii) a protogenic solvent, and (iii) at least one organic compoundselected from the group consisting of polar aprotic solvents having adonor number of no more than 24 and neutral solvents, and furthercomprising (iv) water; wherein the weight ratio of (i) HF (hydrogenfluoride)/(ii) protogenic solvent/(iii) said at least one organiccompound selected from the group consisting of polar aprotic solventshaving a donor number of no more than 24 and neutral solvents/(iv) wateris in the range of (i) 0.05 to 5 mass %/(ii) 1 to 98.93 mass %/(iii) 1to 98.93 mass %/(iv) 0.02 to 90 mass %.

Item 42: A removing solution according to item 35, comprising (i) HF,(ii) a protogenic solvent, (iii) at least one organic compound selectedfrom the group consisting of polar aprotic solvents having a donornumber of no more than 24 and neutral solvents, and (iv) water, andfurther comprising at least one member selected from the groupconsisting of (v) acids, (vi) polar protophilic solvents having a donornumber of at least 25, and (vii) fluorine-containing organic compounds;wherein the weight ratio of (i) HF/(ii) protogenic solvent/(iii) said atleast one organic compound selected from the group consisting of polaraprotic solvents having a donor number of no more than 24 and neutralsolvents/(iv) water/(v) acid/(vi) polar protophilic solvent/(vii)fluorine-containing organic compound is in the range of (i) 0.05 to 5mass %/(ii) 1 to 98.83 mass %/(iii) 1 to 98.83 mass %/(iv) 0.02 to 90mass %/(v) 0 to 10 mass %/(vi) 0 to 50 mass %/(vii) 0 to 70 mass % (withthe total amount of acid, polar protophilic solvent having a donornumber of at least 25, and fluorine-containing organic compound being0.1 to 74.93 mass %).

Item 43: A removing solution according to item 35, comprising (i) HF,(ii) a protogenic solvent, (iii) at least one organic compound selectedfrom the group consisting of polar aprotic solvents having a donornumber of no more than 24 and neutral solvents, (iv) water, and at leastone member selected from the group consisting of (v) acids, (vi) polarprotophilic solvents having a donor number of at least 25, and (vii)fluorine-containing organic compounds, and further comprising ammoniaand/or amine(s); wherein the weight ratio of (i) HF/(ii) protogenicsolvent/(iii) said at least one organic compound selected from the groupconsisting of polar aprotic solvents having a donor number of no morethan 24 and neutral solvents/(iv) water/(v) acid/(vi) polar protophilicsolvent/(vii) fluorine-containing organic compound/(viii) ammonia and/oramine is in the range of (i) 0.05 to 5 mass %/(ii) 1 to 98.73 mass%/(iii) 1 to 98.73 mass %/(iv) 0.02 to 90 mass %/(v) 0 to 10 mass %/(vi)0 to 50 mass %/(vii) 0 to 70 mass %/(viii) 0.05 to 10 mass % (with thetotal amount of acid, polar protophilic solvent having a donor number ofat least 25, and fluorine-containing organic compound being 0.1 to 74.83mass %).

Item 44: A removing solution according to item 35, comprising (i) HF,(ii) at least one organic compound selected from the group consisting ofpolar aprotic solvents having a donor number of no more than 24, neutralsolvents, and protogenic solvents, and (iii) water; wherein the weightratio of (i) HF (hydrogen fluoride)/(ii) said at least one organiccompound selected from the group consisting of polar aprotic solventshaving a donor number of no more than 24, neutral solvents, andprotogenic solvents/(iii) water is in the range of (i) 0.05 to 5 mass%/(ii) 85 to 99.93 mass %/(iii) 0.02 to 10 mass %.

Item 45: A removing solution according to item 35, comprising (i) HF,(ii) at least one organic compound selected from the group consisting ofpolar aprotic solvents having a donor number of no more than 24, neutralsolvents, and protogenic solvents, and (iii) water, and furthercomprising at least one member selected from the group consisting ofacids, polar protophilic solvents having a donor number of at least 25,and fluorine-containing organic compounds; wherein the weight ratio of(i) HF/(ii) said at least one organic compound selected from the groupconsisting of polar aprotic solvents having a donor number of no morethan 24, neutral solvents, and protogenic solvents/(iii) water/(iv)acid/(v) polar protophilic solvent having a donor number of at least25/(vi) fluorine-containing organic compound is in the range of (i) 0.05to 5 mass %/(ii) 25 to 99.83 mass %/(iii) 0.02 to 10 mass %/(iv) 0 to 10mass %/(v) 0 to 50 mass %/(vi) 0 to 70 mass % (with the total amount ofacid, polar protophilic solvent having a donor number of at least 25,and fluorine-containing organic compound being 0.1 to 74.93 mass %).

Item 46: A removing solution according to item 35, comprising (i) HF,(ii) at least one organic compound selected from the group consisting ofpolar aprotic solvents having a donor number of no more than 24, neutralsolvents, and protogenic solvents, (iii) water, and at least one memberselected from the group consisting of (iv) acids, (v) polar protophilicsolvents having a donor number of at least 25, and (vi)fluorine-containing organic compounds, and further comprising (vii)ammonia and/or amine(s); wherein the weight ratio of (i) HF/(ii) said atleast one organic compound selected from the group consisting of polaraprotic solvents having a donor number of no more than 24, neutralsolvents, and protogenic solvents/(iii) water/(iv) acid/(v) polarprotophilic solvent/(vi) fluorine-containing organic compound/(viii)ammonia and/or amine is in the range of (i) 0.05 to 5 mass %/(ii) 25 to99.78 mass %/(iii) 0.02 to 10 mass %/(iv) 0 to 10 mass %/(v) 0 to 50mass %/(vi) 0 to 70 mass %/(vii) 0.05 to 10 mass % (with the totalamount of said at least one member selected from the group consisting ofacids, polar protophilic solvents having a donor number of at least 25,and fluorine-containing organic compounds being 0.1 to 74.88 mass %).

Item 47: A removing solution according to item 40, wherein the neutralsolvents are alcohols; the protogenic solvent is at least one memberselected from the group consisting of monocarboxylic acids,polycarboxylic acids, and sulfonic acids; and the polar aprotic solventshaving a donor number of no more than 24 are at least one memberselected from the group consisting of esters, ethers, ketones, and acidanhydrides.

Item 48: A removing solution according to item 47, wherein (I) as theneutral solvents, the alcohols are methyl alcohol, ethyl alcohol,propanol, isopropanol, t-butanol, allyl alcohol, ethylene glycol,propylene glycol, ethylene glycol monomethyl ether, ethylene glycolmonoethyl ether, ethylene glycol monopropyl ether, ethylene glycolmonoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycolmonoisobutyl ether, diethylene glycol monomethyl ether, diethyleneglycol monoethyl ether, diethylene glycol monopropyl ether, diethyleneglycol monoisopropyl ether, diethylene glycol monobutyl ether,diethylene glycol monoisobutyl ether, triethylene glycol monomethylether, triethylene glycol monoethyl ether, triethylene glycol monopropylether, triethylene glycol monoisopropyl ether, triethylene glycolmonobutyl ether, triethylene glycol monoisobutyl ether, polyethyleneglycol monomethyl ether, propylene glycol monomethyl ether, propyleneglycol monoethyl ether, propylene glycol monopropyl ether, propyleneglycol monoisopropyl ether, propylene glycol monoisobutyl ether,propylene glycol monobutyl ether, dipropylene glycol monomethyl ether,dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether,dipropylene glycol monoisopropyl ether, tripropylene glycol monomethylether, and ethylene glycol monoallyl ether; (II) as the protogenicsolvents, the monocarboxylic acids are formic acid, acetic acid,propionic acid, butyric acid, isobutyric acid, monochloroacetic acid,dichloroacetic acid, trichloroacetic acid, monofluoroacetic acid,difluoroacetic acid, trifluoroacetic acid, α-chlorobutyric acid,β-chlorobutyric acid, γ-chlorobutyric acid, lactic acid, glycolic acid,pyruvic acid, glyoxalic acid, methacrylic acid, and acrylic acid; thepolycarboxylic acids are oxalic acid, succinic acid, adipic acid, andcitric acid; and the sulfonic acids are methanesulfonic acid,benzenesulfonic acid, toluenesulfonic acid, and trifluoromethanesulfonicacid; (III) as the polar aprotic solvents having a donor number of nomore than 24, the esters are methyl acetate, ethyl acetate, butylacetate, propylene carbonate, ethylene carbonate, ethylene sulfite,lactone, tributyl phosphate, and trimethyl phosphate; the ethers aredioxane, trioxane, diglyme, 1,2-dimethoxyethane, tetrahydrofuran,diethyl ether, dimethoxymethane, dimethoxypropane, diethoxymethane,1,1-dimethoxyethane, ethylene glycol methyl ethyl ether, ethylene glycoldiethyl ether, diethylene glycol dimethyl ether, diethylene glycolmethyl ethyl ether, diethylene glycol diethyl ether, triethylene glycoldimethyl ether, triethylene glycol ethyl methyl ether, triethyleneglycol diethyl ether, tetraethylene glycol dimethyl ether, tetraethyleneglycol diethyl ether, polyethylene glycol dimethyl ether, ethyleneglycol monomethyl ether acetate, ethylene glycol monoethyl etheracetate, diethylene glycol monomethyl ether acetate, and diethyleneglycol monoethyl ether acetate; the ketones are acetone; and the acidanhydrides are acetic anhydride.

Item 49: A removing solution according to item 42, 43, 45, or 46,wherein the acids are at least one member selected from the groupconsisting of hydrogen chloride, hydrogen bromide, hydrogen iodide,aqueous solutions thereof, sulfuric acid, nitric acid, phosphoric acid,and carboxylic acid.

Item 50: A removing solution according to item 42, 43, 45, or 46,wherein the fluorine-containing organic compounds arefluorine-containing ethers such as CHF2CF2OCH2CF3 and CHF2CF2OCH4; andhydrochlorofluorocarbons (HCFCs) such as CH3CCl2F and CClF2CF2CHClF.

Item 51: A removing solution according to item 42, 43, 45, or 46,wherein the polar protophilic solvents having a donor number of at least25 are at least one member selected from the group consisting of amidessuch as dimethylformamide, dimethylacetamide, hexamethylphosphorictriamide, N-methyl-2-pyrrolidone, 1,1,3,3-tetramethylurea,N-methylpropionamide, and dimethyl imidazolidinone; and sulfur compoundssuch as dimethyl sulfoxide, sulfolane, dimethylthioformamide, andN-methylthiopyrrolidone.

Item 52: A removing solution according to any of items 40 to 46, whereinthe solution comprises a carboxylic acid as a protogenic solvent; and atleast one member selected from the group consisting of alcohols asneutral solvents, and esters and ethers as polar aprotic solvents havinga donor number of no more than 24.

Item 53: A removing solution according to item 52, wherein thecarboxylic acid is acetic acid.

Item 54: A removing solution according to item 47, wherein the solutioncomprises an alcohol as a neutral solvent; and at least one memberselected from the group consisting of esters and ethers as polar aproticsolvents having a donor number of no more than 24.

Item 55: A removing solution according to item 47, wherein the alcoholsare at least one member selected from the group consisting of propanol,isopropanol, t-butanol, allyl alcohol, ethylene glycol, ethylene glycolmonomethyl ether, ethylene glycol monoethyl ether, ethylene glycolmonopropyl ether, ethylene glycol monoisopropyl ether, ethylene glycolmonobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycolmonomethyl ether, diethylene glycol monoethyl ether, diethylene glycolmonopropyl ether, diethylene glycol monoisopropyl ether, diethyleneglycol monobutyl ether, diethylene glycol monoisobutyl ether,triethylene glycol monomethyl ether, triethylene glycol monoethyl ether,triethylene glycol monopropyl ether, triethylene glycol monoisopropylether, triethylene glycol monobutyl ether, triethylene glycolmonoisobutyl ether, polyethylene glycol monomethyl ether, propyleneglycol monomethyl ether, propylene glycol monoethyl ether, propyleneglycol monopropyl ether, propylene glycol monoisopropyl ether, propyleneglycol monoisobutyl ether, propylene glycol monobutyl ether, dipropyleneglycol monomethyl ether, dipropylene glycol monoethyl ether, dipropyleneglycol monopropyl ether, dipropylene glycol monoisopropyl ether,tripropylene glycol monomethyl ether, and ethylene glycol monoallylether.

Item 56: A removing solution according to any of items 40 to 46, whereinthe solution comprises at least one member selected from the groupconsisting of esters and ethers as polar aprotic solvents having a donornumber of no more than 24.

Item 57: A removing solution according to any of items 40 to 46, whereinthe esters are at least one member selected from the group consisting ofmethyl acetate, ethyl acetate, butyl acetate, propylene carbonate, andethylene carbonate; and the ethers are at least one member selected fromthe group consisting of 1,2-dimethoxyethane, tetrahydrofuran, dioxane,trioxane, diglyme, ethylene glycol methyl ethyl ether, ethylene glycoldiethyl ether, diethylene glycol dimethyl ether, diethylene glycolmethyl ethyl ether, diethylene glycol diethyl ether, triethylene glycoldimethyl ether, triethylene glycol ethyl methyl ether, triethyleneglycol diethyl ether, tetraethylene glycol dimethyl ether, tetraethyleneglycol diethyl ether, polyethylene glycol dimethyl ether, ethyleneglycol monomethyl ether acetate, ethylene glycol monoethyl etheracetate, diethylene glycol monomethyl ether acetate, and diethyleneglycol monoethyl ether acetate.

Item 58: A removing solution according to item 44, comprising HF, aceticacid, and water; wherein the weight ratio of HF/acetic acid/water is inthe range of 0.05 to 5 mass %/85 to 99.93 mass %/0.02 to 10 mass %.

Item 59: A removing solution according to item 44, comprising HF,isopropanol, and water; wherein the weight ratio of HF/isopropanol/wateris in the range of 1 to 7 mass %/88 to 98.5 mass %/0.5 to 5 mass %.

Item 60: A removing solution according to item 44, comprising HF, aceticacid, isopropanol, and water; wherein the weight ratio of HF/aceticacid/isopropanol/water is in the range of 0.05 to 6 mass %/1 to 98.93mass %/1 to 98.93 mass %/0.02 to 12 mass %.

Item 61: A removing solution according to item 44, comprising HF,1,2-dimethoxyethane, and water; wherein the weight ratio ofHF/1,2-dimethoxyethane/water is in the range of 0.50 to 5 mass %/85.00to 99.3 mass %/0.02 to 10 mass %.

Item 62: A removing solution according to item 44, comprising HF; atleast one member selected from the group consisting of methyl acetate,ethyl acetate, and butyl acetate; and water; wherein the weight ratio ofHF/said at least one member selected from the group consisting of methylacetate, ethyl acetate, and butyl acetate/water is in the range of 0.50to 5 mass %/85.00 to 99.30 mass %/0.02 to 10 mass %.

Item 63: A removing solution according to item 44, comprising HF,1,4-dioxane, and water; wherein the weight ratio of HF/1,4-dioxane/wateris in the range of 0.50 to 5 mass %/85.00 to 99.3 mass %/0.2 to 10 mass%.

Item 64: A removing solution according to item 44, comprising HF;1,4-dioxane and at least one member selected from the group consistingof acetic anhydride and acetic acid; and water; wherein the weight ratioof HF/1,4-dioxane and said at least one member selected from the groupconsisting of acetic anhydride and acetic acid/water is in the range of0.50 to 6 mass %/82.00 to 99.30 mass %/0.2 to 12 mass %.

Item 65: A removing solution according to item 44, comprising HF; atleast one member selected from the group consisting of ethylene glycolmonomethyl ether, ethylene glycol diethyl ether, diethylene glycolmethyl ethyl ether, tetraethylene glycol dimethyl ether, polyethyleneglycol dimethyl ether, ethylene glycol monoallyl ether, diethyleneglycol monobutyl ether, ethylene glycol butyl ether, triethylene glycolmonobutyl ether, diethylene glycol diethyl ether, diethylene glycoldimethyl ether, triethylene glycol dimethyl ether, diethylene glycolmonoisobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycolmonoisopropyl ether, diethylene glycol monomethyl ether, dipropyleneglycol monomethyl ether, propylene glycol monomethyl ether, tripropyleneglycol monomethyl ether, ethylene glycol monoethyl ether, polyethyleneglycol monomethyl ether, triethylene glycol monomethyl ether, propyleneglycol monopropyl ether, and ethylene glycol methyl ethyl ether; andwater; wherein the weight ratio of HF/said at least one member selectedfrom the group consisting of ethylene glycol monomethyl ether, ethyleneglycol diethyl ether, diethylene glycol methyl ethyl ether,tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether,ethylene glycol monoallyl ether, diethylene glycol monobutyl ether,ethylene glycol butyl ether, triethylene glycol monobutyl ether,diethylene glycol diethyl ether, diethylene glycol dimethyl ether,triethylene glycol dimethyl ether, diethylene glycol monoisobutyl ether,ethylene glycol monoisobutyl ether, ethylene glycol monoisopropyl ether,diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether,propylene glycol monomethyl ether, tripropylene glycol monomethyl ether,ethylene glycol monoethyl ether, polyethylene glycol monomethyl ether,triethylene glycol monomethyl ether, propylene glycol monopropyl ether,and ethylene glycol methyl ethyl ether/water is in the range of 0.50 to5 mass %/85.00 to 99.30 mass %/0.20 to 10 mass %.

Item 66: A removing solution according to item 35, comprising HF,methanesulfonic acid, and water; wherein the weight ratio ofHF/methanesulfonic acid/water is in the range of more than 0 and notmore than 5 mass %/at least 45 and less than 100 mass %/more than 0 andnot more than 50 mass %.

Item 67: A removing method comprising removing etching residue whileleaving low-k film that has been damaged by a plasma process, by the useof the removing solution of item 1 or 35.

Item 68: A method according to item 15 or 67, comprising performing aremoval treatment under an atmosphere (substantially in inert gas)wherein one or more inert gases are mixed such that the atmosphere hasan oxygen partial pressure below the oxygen partial pressure in air.

Item 69: A rinse treatment method for removing a removing solution froman object treated by the method of item 15 or 67, comprising performinga rinse treatment using water wherein one or more inert gases aredissolved such that the oxygen partial pressure in the water is belowthe oxygen partial pressure in air-saturated solution, under anatmosphere (substantially in inert gas) wherein one or more inert gasesare mixed such that the atmosphere has an oxygen partial pressure belowthe oxygen partial pressure in air.

Item 70: A removal-treated object that can be obtained by treatmentaccording to the removing method of item 67 or 68 and the rinsetreatment method of item 69.

Item 71: A cleaning solution for a via hole or a capacitor according toitem 20, wherein the removing solution of item 35 is used to clean thevia hole or the capacitor.

Item 72: A method of cleaning a via hole according to item 29 or amethod of cleaning a capacitor according to item 32, comprising usingthe cleaning solution for a via hole or a capacitor of item 71.

Item 73: A cleaned object that can be obtained by cleaning treatmentusing the cleaning solution for a via hole or a capacitor of item 71.

The present invention relates to a resist-removing solution and aresist-removing method for low-k film; a cleaning solution and acleaning method for via holes; and a cleaning solution and a cleaningmethod for capacitors.

The removing solution and the cleaning solution of the invention arecompositions comprising hydrogen fluoride (HF) and at least one memberselected from the group consisting of organic acids and organicsolvents.

Examples of organic acids include monocarboxylic acids such as aceticacid, propionic acid, butyric acid, isobutyric acid, valeric acid,caproic acid, caprylic acid, monochloroacetic acid, dichloroacetic acid,trichloroacetic acid, monofluoroacetic acid, difluoroacetic acid,trifluoroacetic acid, α-chlorobutyric acid, β-chlorobutyric acid,γ-chlorobutyric acid, lactic acid, glycolic acid, pyruvic acid,glyoxalic acid, and acrylic acid; sulfonic acids such as methanesulfonicacid and toluenesulfonic acid; and polycarboxylic acids such as oxalicacid, succinic acid, adipic acid, tartaric acid, and citric acid. Amongthese organic acids, acetic acid is especially preferable.

Examples of organic solvents include:

monohydric alcohols such as methanol, ethanol, isopropanol (IPA),1-propanol, 1-butanol, 2-butanol, t-butanol, 2-methyl-1-propanol,1-pentanol, 1-hexanol, 1-heptanol, 4-heptanol, 1-octanol, 1-nonylalcohol, 1-decanol, 1-dodecanol, lauryl alcohol, and cyclohexanol;

polyols such as ethylene glycol, diethylene glycol, 1,2-propanediol,propylene glycol, 2,3-butanediol, and glycerin;

ketones such as acetone, acetylacetone, methyl ethyl ketone, methylisobutyl ketone, cyclohexanone, diethyl ketone, and diisobutyl ketone;

amides such as N-methylformamide, N,N-dimethylformamide,N-methylacetamide, and N,N-dimethylacetamide;

nitriles such as acetonitrile, propionitrile, butyronitrile,isobutyronitrile, and benzonitrile;

aldehydes such as formaldehyde, acetaldehyde, and propionaldehyde;

alkylene glycol monoalkyl ethers such as ethylene glycol monomethylether and ethylene glycol monoethyl ether;

ethers such as tetrahydrofuran, dioxane, diisopropyl ether, dibutylether, tetrahydropyran, anisole, 1,2-dimethoxyethane, and diethyleneglycol dimethyl ether;

esters such as methyl acetate, ethyl acetate, propyl acetate, isopropylacetate, butyl acetate, isobutyl acetate, pentyl acetate, hexyl acetate,methyl propionate, ethyl propionate, propyl propionate, isopropylpropionate, butyl propionate, isobutyl propionate, pentyl propionate,hexyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate,isopropyl butyrate, butyl butyrate, isobutyl butyrate, pentyl butyrate,hexyl butyrate, methyl isobutyrate, ethyl isobutyrate, propylisobutyrate, isopropyl isobutyrate, butyl isobutyrate, isobutylisobutyrate, pentyl isobutyrate, hexyl isobutyrate, methyl valerate,ethyl valerate, propyl valerate, isopropyl valerate, butyl valerate,isobutyl valerate, pentyl valerate, hexyl valerate, methyl isovalerate,ethyl isovalerate, propyl isovalerate, isopropyl isovalerate, butylisovalerate, isobutyl isovalerate, pentyl isovalerate, hexylisovalerate, methyl caproate, ethyl caproate, propyl caproate, isopropylcaproate, butyl caproate, isobutyl caproate, pentyl caproate, hexylcaproate, methyl caprylate, ethyl caprylate, propyl caprylate, isopropylcaprylate, butyl caprylate, isobutyl caprylate, pentyl caprylate, hexylcaprylate, methyl octanoate, ethyl octanoate, propyl octanoate,isopropyl octanoate, butyl octanoate, isobutyl octanoate, pentyloctanoate, hexyl octanoate, methyl nonanoate, ethyl nonanoate, propylnonanoate, isopropyl nonanoate, butyl nonanoate, isobutyl nonanoate,pentyl nonanoate, hexyl nonanoate, methyl decanoate, ethyl decanoate,propyl decanoate, isopropyl decanoate, butyl decanoate, isobutyldecanoate, pentyl decanoate, hexyl decanoate, methyl dodecanoate, ethyldodecanoate, propyl dodecanoate, isopropyl dodecanoate, butyldodecanoate, isobutyl dodecanoate, pentyl dodecanoate, hexyldodecanoate, methyl laurate, ethyl laurate, propyl laurate, isopropyllaurate, butyl laurate, isobutyl laurate, pentyl laurate, hexyl laurate,methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate,butyl acrylate, isobutyl acrylate, pentyl acrylate, hexyl acrylate,monomethyl oxalate, dimethyl oxalate, monoethyl oxalate, diethyloxalate, monopropyl oxalate, dipropyl oxalate, monobutyl oxalate,dibutyl oxalate, monomethyl succinate, dimethyl succinate, monoethylsuccinate, diethyl succinate, monopropyl succinate, dipropyl succinate,monobutyl succinate, dibutyl succinate, monomethyl adipate, dimethyladipate, monoethyl adipate, diethyl adipate, monopropyl adipate,dipropyl adipate, monobutyl adipate, dibutyl adipate, monomethyltartrate, dimethyl tartrate, monoethyl tartrate, diethyl tartrate,monopropyl tartrate, dipropyl tartrate, monobutyl tartrate, dibutyltartrate, monomethyl citrate, dimethyl citrate, monoethyl citrate,diethyl citrate, monopropyl citrate, dipropyl citrate, monobutylcitrate, dibutyl citrate, dimethyl phthalate, diethyl phthalate,dipropyl phthalate, dibutyl phthalate, dipentyl phthalate, dihexylphthalate, diheptyl phthalate, dioctyl phthalate, dinonyl phthalate,didecyl phthalate, didodecyl phthalate, dimethyl terephthalate, diethylterephthalate, dipropyl terephthalate, dibutyl terephthalate, dipentylterephthalate, dihexyl terephthalate, diheptyl terephthalate, dioctylterephthalate, dinonyl terephthalate, didecyl terephthalate, didodecylterephthalate, propylene carbonate, and γ-butyrolactone;

hydrocarbons such as hexane, cyclohexane, octane, isooctane, benzene,and toluene;

halogen compounds such as chloroform, o-dichlorobenzene,perfluorohexane, and perfluoromethylcyclohexane;

fluorinated alcohols such as trifluoroethanol (e.g. CF3CH2OH),pentafluoropropanol (e.g. CF3CF2CH2OH), and 2,2,3,3-tetrafluoropropanol;

acetic anhydride, dimethyl sulfoxide, sulfolane, and nitromethane;

nitrogen-containing organic solvents such as tetramethylurea andN-methyl-2-pyrrolidone; and

phosphate ester solvents such as dimethyl phosphate, dibutyl phosphate,diphenyl phosphate, dibenzyl phosphate, trimethyl phosphate, triethylphosphate, tripropyl phosphate, tributyl phosphate, and triphenylphosphate.

Among these organic solvents, preferable examples are isopropanol (IPA),1-propanol, 1-butanol, 2-butanol, t-butanol, 2-methyl-1-propanol,1-pentanol, 1-hexanol, ethylene glycol, diethylene glycol,1,2-propanediol, cyclohexanol, propylene glycol, glycerin, dibutylether, N-methylformamide, N,N-dimethylformamide, N-methylacetamide,N,N-dimethylacetamide, N-methyl-2-pyrrolidone, tetrahydrofuran, dioxane,methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butylacetate, isobutyl acetate, pentyl acetate, hexyl acetate, dimethylsulfoxide, sulfolane, octane, cyclohexane, benzene, and toluene.Especially preferable organic solvents are IPA, hexanol, cyclohexanol,lauryl alcohol, propylene glycol, diethylene glycol, ethylene glycol,glycerin, dibutyl ether, butyl acetate, octane, cyclohexane, benzene,and toluene. Methanol and ethanol can be additionally used in an amountthat does not corrode wiring materials such as Cu.

When the removing solution of the present invention is used forultrasonic cleaning, the organic solvent is preferably at least onemember selected from the group consisting of esters, ketones, monohydricalcohols, polyhydric alcohols, amides, ethers, alkylene glycol monoalkylethers, phosphate esters, and nitrogen-containing compounds.

In view of properties for removing resist or cleaning via holes andcontact holes, organic acids or organic solvents preferably have an SPvalue of about 7 to about 17, more preferably about 8 to about 17, andeven more preferably about 9 to about 17.

In the removing solution and the cleaning solution of the invention, theamount of HF is not limited and can be suitably set according to thekind of other components. When the removing solution/cleaning solutioncontains organic acid(s) (i.e. when it contains organic acid(s) but noorganic solvent, or when it contains organic acid(s) and organicsolvent(s)), the amount of HF is about 0.01 to about 5 mass %,preferably about 0.05 to about 3 mass %, and more preferably about 0.1to about 1 mass %, based on the total amount of the removingsolution/cleaning solution (hereinafter, the amount of each component isindicated based on the total amount of the removing solution/cleaningsolution). When the solution does not contain any organic acid (i.e.when it contains organic solvent(s) but no organic acid), the amount ofHF is about 0.01 to about 10 mass %, preferably about 0.05 to about 5mass %, and more preferably about 0.1 to about 3 mass %.

When the removing solution/cleaning solution contains water, the amountof water is no more than about 70 mass %, preferably no more than about50 mass %, and more preferably no more than about 5 mass %.

The amount of said at least one member selected from the groupconsisting of organic acids and organic solvents is about 30 to about99.99 mass %, preferably about 50 to about 99.9 mass %, more preferablyabout 90 to about 99.9 mass %, and even more preferably about 95 toabout 99.9 mass %.

Usually HF is used in the form of dilute hydrofluoric acid (50 mass %aqueous solution); however, without water, 100% HF may be used.

Preferable examples of removing solutions, cleaning solutions, andamounts of components in the present invention are given below.

In this specification, the amount of “HF” means the amount of anhydrousHF unless otherwise indicated.

HF/organic acid/water=0.01-5 mass %/49-99.9 mass %/0-50 mass %

HF/organic solvent/water=0.01-10 mass %/49-99.9 mass %/0-50 mass %

The following are more preferable examples of removing solutions,cleaning solutions, and amounts of components in the invention.

HF/acetic acid/water=0.05-5 mass %/90-99.95 mass %/0-5 mass %

HF/IPA/water=0.1-10 mass %/80-99.9 mass %/0-10 mass %

HF/hexanol/water=0.1-10 mass %/80-99.9 mass %/0-10 mass %

HF/lauryl alcohol/water=0.1-10 mass %/80-99.9 mass %/0-10 mass %

HF/propylene glycol/water=0.1-10 mass %/80-99.9 mass %/0-10 mass %

HF/diethylene glycol/water=0.1-10 mass %/80-99.9 mass %/0-10 mass %

HF/ethylene glycol/water=0.1-10 mass %/80-99.9 mass %/0-10 mass %

HF/glycerin/water=0.1-10 mass %/80-99.9 mass %/0-10 mass %

HF/cyclohexanol/water=0.1-10 mass %/80-99.9 mass %/0-10 mass %

HF/dibutyl ether/water=0.1-10 mass %/80-99.9 mass %/0-10 mass %

HF/butyl acetate/water=0.1-10 mass %/80-99.9 mass %/0-10 mass %

HF/octane/water=0.1-10 mass %/80-99.9 mass %/0-10 mass %

HF/cyclohexane/water=0.1-10 mass %/80-99.9 mass %/0-10 mass %

HF/benzene/water=0.1-10 mass %/80-99.9 mass %/0-10 mass %HF/toluene/water=0.1-10 mass %/80-99.9 mass %/0-10 mass %

The following are even more preferable examples of removing solutions,cleaning solutions, and amounts of components in the invention.

HF/acetic acid/water=0.1-3 mass %/94-99.99 mass %/0-3 mass %

HF/IPA/water=0.1-5 mass %/90-99.9 mass %/0-5 mass %

HF/hexanol/water=0.1-5 mass %/90-99.9 mass %/0-5 mass %

HF/lauryl alcohol/water=0.1-5 mass %/90-99.9 mass %/0-5 mass %

HF/propylene glycol/water=0.1-5 mass %/90-99.9 mass %/0-5 mass %

HF/diethylene glycol/water=0.1-5 mass %/90-99.9 mass %/0-5 mass %

HF/ethylene glycol/water=0.1-5 mass %/90-99.9 mass %/0-5 mass %

HF/glycerin/water=0.1-5 mass %/90-99.9 mass %/0-5 mass %

HF/cyclohexanol/water=0.1-5 mass %/90-99.9 mass %/0-5 mass %

HF/dibutyl ether/water=0.1-5 mass %/90-99.9 mass %/0-5 mass %

HF/butyl acetate/water=0.1-5 mass %/90-99.9 mass %/0-5 mass %

HF/octane/water=0.1-5 mass %/90-99.9 mass %/0-5 mass %

HF/cyclohexane/water=0.1-5 mass %/90-99.9 mass %/0-5 mass %

HF/benzene/water=0.1-5 mass %/90-99.9 mass %/O-5 mass %

HF/toluene/water=0.1-5 mass %/90-99.9 mass %/0-5 mass %

The removing solution and the cleaning solution of the present inventioncan be used for ultrasonic cleaning. When the solution is used for thispurpose, it is desirable that the solution contain at least one memberselected from the group consisting of ammonia and amines.

Examples of amines are hydroxylamines; alkanolamines; primary,secondary, and tertiary amines represented by NR₃; alicyclic amines;heterocyclic amines; etc.

Specifically, examples of hydroxylamines include hydroxylamine andN,N-diethylhydroxylamine.

Examples of alkanolamines include monoethanolamine, diethanolamine, andtriethanolamine.

In NR₃, the three Rs may be the same or different and each individuallyrepresents a hydrogen atom or a hydrocarbon group optionally substitutedwith fluorine, provided that the three Rs are not all hydrogen atoms.

Examples of hydrocarbon groups optionally substituted with fluorineinclude linear and branched C₁ to C₁₈, preferably C₁ to C₁₂, alkylgroups; and phenyl groups optionally substituted with fluorine. Amongsuch examples, unsubstituted C₁ to C₁₈ alkyl groups are preferable.

The compounds represented by NR₃ are, for example, aliphatic amines,including primary amines such as methylamine and ethylamine, secondaryamines such as dimethylamine and diethylamine, and tertiary amines suchas trimethylamine and triethylamine. Examples of aromatic amines areaniline and methylaniline.

Examples of alicyclic amines are cyclohexylamine and dicyclohexylamine;and examples of heterocyclic amines are pyrrole, pyrrolidine,pyrrolidone, pyridine, morpholine, pyrazine, piperidine,N-hydroxyethylpiperidine, oxazole, and thiazole.

When ammonia and/or amines are present, mixing of the solution formssalts with the ratio of hydrofluoric acid to ammonia/amine being either1 to 1 or 1 to 2. In the removing solution/cleaning solution of thepresent invention, hydrofluoric acid, and ammonia and/or amines may bepresent as salts.

When the solution contains ammonia and/or amines, the molar ratio ofammonia and amines is preferably lower than that of hydrofluoric acid.For example, in the removing solution/cleaning solution that containsthese two kinds of components, the molar ratio of hydrofluoricacid/ammonia and amines is about 1/0.01 to 1/1.

When the removing solution/cleaning solution contains an amine, apreferable example of the solution and its components is as follows:

HF/ammonia and/or amines/organic solvent/water=0.01-10 mass %/0.01-30mass %/49-99.9 mass %/0-50 mass %

The removing solution and the cleaning solution of the present inventionmay contain at least one surfactant selected from the group consistingof anionic surfactants, cationic surfactants, and nonionic surfactants.Although the amount of surfactant is not limited as long as the effectsof the present invention can be achieved, it is usually about 0.0001 toabout 10 mass %, preferably about 0.001 to about 5 mass %, andespecially preferably about 0.01 to about 1 mass %.

The resist-removing solution of the invention is preferably acomposition that can etch a SiN film to a depth of at least 1 Å. Thecleaning solution of the invention is preferably a composition that canetch a TiN film to a depth of at least 0.01 Å.

The removing solution of the invention can be advantageously used forresists (including negative and positive resists) used in the etching oflow-k films and modified resists.

The resists removed by the method of the present invention are thoseknown resists, such as KrF (Krypton F), ArF, and F₂ resists, that havebeen subjected to an etching treatment with an etching gas such as C4F8.

In this specification, “resist” includes modified resist, which has allor part of the resist surface modified by the etching process. Theresist-removing solution of the present invention can remove suchmodified resist.

When the polymer produced by the polymerization of etching gas in theetching process is present in a trench or a hole formed by etching, thepolymer may be removed at the same time as resist.

In this specification, low-k film is a film that can be damaged by O₂plasma ashing. Specifically, it is an insulating film having adielectric constant greater than 1 but not greater than about 4,preferably not greater than about 3, more preferably not greater thanabout 2.8, and even more preferably not greater than about 2.6. Examplesof low-k film include “Black Diamond” (trade name, product of AppliedMaterials, Inc.), “CORAL” (trade name, product of Novellus Systems,Inc.), “LKD” series (trade name, product of JSR Corporation), “Aurora”(trade name, product of ASM), “HSG” series (trade name, product ofHitachi Chemical Co., Ltd.), “Nanoglass” (trade name, product ofHonewell), “IPS” (trade name, product of Catalysts & ChemicalsIndustries Co., Ltd.), “Z₃M” (trade name, product of Dow CorningCorporation), “XLK” (trade name, product of Dow Corning Corporation),and “FOx” (trade name, product of Dow Corning Corporation).

Examples of the above-mentioned resist include KrF (Krypton F), ArF, andF₂ resists; however, the resist is not limited to these.

In the method of the present invention, for example, after forming alow-k film on a semiconductor substrate (such as SiN, copper, TaN, andSiC), forming resist, followed by photolithography for forming patterns,and etching the low-k film according to the patterns, the resist(including modified resist) can be removed by bringing it into contactwith the removing solution of the present invention. The removingsolution of the invention is a liquid used to treat an object havingresist (including modified resist) adhering to a hole or a trench formedin the low-k film and resist, and thereby to remove the resist (and themodified resist). The object may have polymers (polymerization productsof etching gas) adhering to the sidewall and/or the bottom of a holeformed in the low-k film by etching.

After forming a low-k film on a substrate, films such as SiN, SiC, andTaN films may be formed on the low-k film and etched together with thelow-k film, if necessary.

An antireflection coating may be formed on the resist and then removedtogether with the resist.

Low-k film and resist usually have a thickness of about 0.01 to about 2μm, and about 0.01 to about 10 μm, respectively. Optional SiN film, SiCfilm, TaN film, and antireflection coatings usually have a thickness ofabout 0.01 to about 2 μm, about 0.001 to about 0.2 μm, about 0.01 toabout 10 μm, and about 0.01 to about 0.1 μm, respectively.

In the method of the present invention, if necessary, light O₂ plasmaashing (for example, O₂ plasma ashing such that the change in dielectricconstant before and after the ashing is preferably no more than about20%, more preferably no more than about 10%, and even more preferably nomore than about 5%) or light H₂ plasma ashing may be performed betweenetching and contact with the removing solution of the invention, to anextent such that the low-k film is not damaged. When light O₂ plasmaashing or light H₂ plasma ashing is performed as pretreatment, even ifthe same removing solution is used, the optimum conditions with respectto temperature, time, etc. may differ from those when resist is removedwithout such ashing after etching.

The method of removing resist using the removing solution of the presentinvention enables the removal of resist (including modified resist)under temperature and time conditions such that low-k film issubstantially undamaged. “Low-k film is substantially undamaged” means,for example, that the change in the physical properties of the low-kfilm before and after the treatment using the removing solution is suchthat the performance of the film when used in a semiconductor substrateis not affected; that the low-k film is substantially unetched at theinterface between the resist and the film, so that the cross-sectionalprofile of a treated object with film layers is substantially unchanged;and/or that the dielectric constant of the low-k film is substantiallyunchanged before and after the treatment using the removing solution.“Low-k film is substantially unetched” means that the low-k film isetched to a depth of preferably no more than about 200 nm, morepreferably no more than about 100 nm, and even more preferably no morethan about 50 nm. “Dielectric constant of the low-k film issubstantially unchanged before and after the treatment using theremoving solution” means that the change in the dielectric constant ispreferably no more than about 20%, more preferably no more than about10%, and even more preferably no more than about 5%.

Treatment with the removing solution can be conducted by, for example,after etching, immersing a substrate in the removing solution of thepresent invention. The immersion conditions are not limited as long asthey can remove resist and substantially do not damage low-k film; theycan be suitably set according to the temperature and kind of removingsolution. For example, when the temperature of a removing solution isabout 15° C. to about 60° C., the immersion time may be about 0.1 toabout 30 minutes, and preferably about 0.5 to about 20 minutes. Morespecifically, when the removing solution is composed of HF/aceticacid/water=0.05-1 mass %/98-99.5 mass %/0-1 mass %, and its temperatureis about 23° C., immersion time may be about 0.1 to about 20 minutes.When the removing solution is composed of HF/ethylamine/ethyleneglycol/water=0.05-2 mass %/0.01-2 mass %/94-99.5 mass %/0-2 mass %, theimmersion time may be about 0.1 to about 20 minutes.

Furthermore, since resist can be removed if the removing solution isbrought into contact with an object to be treated, the solution, forexample, may be supplied from above an object that is rotated whilebeing cleaned; or the solution may be sprayed over an object forcleaning.

When resist cannot be easily removed due to conditions such as the kindof resist and etching, the treatment with the removing solution of theinvention may be conducted by, for example, immersing the object to betreated in the solution and performing ultrasonic cleaning.

The conditions for ultrasonic cleaning are not limited as long as theycan remove resist. When the temperature of a removing solution is about23° C., ultrasonic cleaning is usually carried out at 20 to 1200 kHz and50 to 3000 W for about 0.1 to about 20 minutes.

More specifically, when the removing solution is composed of HF/aceticacid/water=0.05-1 mass %/98-99.5 mass %/0-1 mass %, and its temperatureis about 23° C., ultrasonic cleaning may be carried out at 20 to 1200kHz and 50 to 3000 W for about 0.1 to about 20 minutes. When theremoving solution is composed of HF/ethylamine/ethyleneglycol/water=0.05-2 mass %/0.05-2 mass %/94-99.5 mass %/0-2 mass %,ultrasonic cleaning may be carried out at 20 to 1200 kHz and 50 to 3000W for about 0.1 to about 20 minutes.

The semiconductor substrate from which resist has been removed using theremoving solution of the invention may be, for example, provided withcopper or aluminum wiring. It can be used to produce varioussemiconductor devices according to conventional methods (such as thosementioned in Toshiroh Doi, ed., Shousetsu Handoutal CMP Gijutsu (2001)).

The cleaning solution of the present invention is capable of removingtitanium compounds (such as titanium fluorides and titanium oxides)and/or polymers generated by dry etching. The cleaning solution of theinvention, therefore, can be used as a via hole cleaning solution, forexample, to remove titanium fluorides, polymers, or the like remainingon the sidewalls and/or the bottoms of via holes, etc. after dry etchingtreatment in semiconductor production processes. The cleaning solutionof the invention can be used, for example, to clean via holes, etc. byremoving titanium compounds and/or polymers (such as titanium fluoridesand titanium oxides) generated in the formation of via holes, etc. Thecleaning solution of the invention is capable of cleaning via holes atlow temperature and in a short time.

Furthermore, the removing solution of the invention is capable ofremoving resist residue, titanium compounds, polymers, etc. generated bydry etching. The removing solution of the invention, therefore, can beused as a capacitor cleaning solution in semiconductor productionprocesses, for example, to remove resist residue, polymers, and titaniumcompounds remaining after the dry etching (and ashing) of an upper orlower electrode metal film (TiN, Ti, etc.) of a metal capacitor. Thecleaning solution of the invention can be used, for example, to cleanvia holes, etc., by removing at least one member selected from the groupconsisting of resist residue, titanium compounds, and polymers that aregenerated in the formation of the metal capacitor, etc., and that adhereto at least one member selected from the group consisting of thesidewall, the bottom, and the surface of an upper or lower electrode.

Titanium compounds are generated when the etching process ofsemiconductor production uses a fluorine-containing gas (such as C₄F₈,etc.) as a dry etching gas, and a titanium-containing substrate (such asTiN, etc.). In the present invention, a “polymer” means a polymerizationproduct of an etching gas in etching. Furthermore, in the presentinvention, “resist residue” means residue generated in ashing after anetching process.

The treatment using the cleaning solution of the present invention canbe conducted by immersing an object to be treated in the solution (theobject being a semiconductor substrate having at least one memberselected from the group consisting of a via hole and a metal capacitorupper or lower electrode, wherein polymers and/or titanium compoundsadhere to the sidewall and/or the bottom of the via hole or whereinresist residue and/or polymers and/or titanium compounds adhere to theupper or lower electrode metal film (TiN, Ti, etc.) of the metalcapacitor). The immersion conditions can be suitably set according tothe kind of cleaning solution. For example, immersion may be carried outunder the conditions of about 15° C. to about 60° C., and preferablyabout room temperature, for about 0.1 to about 20 minutes. In this case,since cleaning can be conducted if the cleaning solution is brought intocontact with an object to be treated, the solution, for example, may besupplied from above an object that is rotated while being cleaned; orthe solution may be sprayed over an object.

When a polymer that is difficult to remove arises due to the etchingconditions, etc., the treatment with the cleaning solution of thepresent invention may be conducted by, for example, immersing the objectto be treated in the solution and performing ultrasonic cleaning. Theconditions for ultrasonic cleaning are not limited. For example, whenthe temperature of the removing solution is about 15° C. to about 60°C., ultrasonic cleaning may be carried out at 20 to 1200 kHz and 50 to3000 W for about 0.1 to about 30 minutes.

More specifically, when the removing solution is composed of HF/aceticacid/water=0.05-1 mass %/98-99.5 mass %/0-1 mass %, and its temperatureis about 23° C., ultrasonic cleaning may be carried out at 20 to 1200kHz and 50 to 3000 W for about 0.5 to about 20 minutes. When theremoving solution is composed of HF/amine or ammonia/ethyleneglycol/water=0.05-2 mass %/0.05-2 mass %/94-99.5 mass %/0-2 mass %,ultrasonic cleaning may be carried out at 20 to 1200 kHz and 50 to 3000W for about 0.5 to about 20 minutes.

A semiconductor substrate wherein via holes and capacitors have beencleaned using the composition of the invention can be adopted to producevarious semiconductor devices according to conventional methods (W.Maly, Atlas of IC Technologies: An Introduction to VLSI Processes(1987), The Benjamin/Cummings Publishing Company Inc.).

Furthermore, in the present invention, a composition comprising asessential components, hydrogen fluoride (HF); and, among organic acidsand organic solvents, at least one member selected from the groupconsisting of polar aprotic solvents having a donor number of no morethan 24, neutral solvents, and protogenic solvents is especiallyeffective for removing resist for low-k film, antireflection coatings,filling materials, and etching residues including these, and forcleaning via holes and capacitors.

In the treatment for removing etching residues including resist, etc.,after dry etching, the removing solution of the invention is acomposition for removing the etching residues under the conditions of(1) etching an insulating film barrier to a depth of 1 to 200 Å, (2)etching low-k film to a depth of 1 to 200 Å, and (3) etching Cu at anetching rate of no more than 5 Å/min. Using this composition, theremoval treatment time is 0.1 to 120 minutes, and particularly 1 to 60minutes. The etching depth of the insulating film barrier and the low-kfilm can be controlled within the above range by the treatment time.

There are two kinds of insulating film barriers: those in which etchingcontinues, and those in which etching tends to stop with the passage oftime. Films in which etching continues are, for example, SiN, SiO2, andSiOC. Films in which etching tends to stop are, for example, SiC andSiCN.

When an insulating film barrier such as SiC and SiCN, in which etchingtends to stop, is etched to a depth of 5 Å, the etching depth of low-kfilm is 5 to 190 Å, and that of Cu is 0.02 to 2 Å.

When an insulating film barrier such as SiN, SiO2, and SiOC, in whichetching continues, is etched to a depth of 50 Å, the etching depth oflow-k film is 35 to 195 Å, and that of Cu is 0.02 to 2 Å.

An insulating film barrier is an insulating film used in the productionof a Cu/low-k multilevel interconnection structure for wiring in asemiconductor device, (1) to provide a hard mask for low-k filmpatterning, (2) to provide a barrier for preventing the diffusion ofcopper, (3) to provide an etch stopper to prevent the etching of low-kfilm, (4) to protect low-k film and improve its adhesion to a base (alower layer film), and (5) to protect low-k film in a copper CMP process(as a cap film), etc. In order to maintain these functions and not todamage the dielectric constant of the low-k film, it is desired that theinsulating film has a low dielectric constant. Examples of insulatingfilm barriers include silicon (Si)-containing compounds such as siliconnitride (SiN), silicon carbide (SiC), and silicon carbide nitride(SiCN).

In addition to the low-k film already described, low-k film may also bea newly formed film having a dielectric constant not greater than 2.4,such as “Orion” (trade name, product of Tricon). Low-k film is mainlyformed by coating or by organic plasma CVD. Low-k film formed by coatingis named after its material, and the low-k film formed by organic plasmaCVD is named after its material and device. “Orion” is a film formed byorganic plasma CVD.

The removing solution of the present invention comprises hydrogenfluoride and at least one member selected from the group consisting ofpolar aprotic solvents having a donor number of no more than 24, neutralsolvents, and protogenic solvents. This removing solution is capable ofcontrolling the etching of wiring metals such as copper; insulating filmbarriers and low-k film; and resist, antireflection coatings, fillingmaterials, and etching residues including these. Specifically, theremoving solution of the invention has the following features: (1) itinhibits the corrosion of metals such as copper; (2) it selectivelyetches insulating film barriers to separate etching residue from theinsulating film barriers or low-k film; (3) it selectively dissolvessilicon nitride (SiN), etc., contained in etching residue; and (4) withan organic solvent, it dissolves organic components in resist,antireflection coatings, and etching residues including these, thusremoving resist, antireflection coatings, filling materials, and etchingresidues including these. Etching residues include auxiliary materialssuch as resist, antireflection coatings, and filling materials, whichare used in the production of semiconductor devices; adhered ordeposited substances such as reaction products and sputtering productsin the processes of dry etching and of ashing after dry etching; andother residues that need to be removed.

Adhered or deposited substances are formed of substances such asfluorocarbon-containing polymers that are generated from the etching gasplasma itself; reaction products that are generated when devicematerials such as resist, antireflection coatings, filling materials,insulating film barriers, low-k film, wiring metals, etc., are exposedto plasma in the etching process; substances that are generated in theprocess of sputtering by plasma ions; etc.

Residues that need to be removed are composed of resist including resistmodified by etching and ashing, antireflection coating, fillingmaterial, etc., which have to be removed and are not needed in processessubsequent to etching. The treatment time for removal and cleaning is0.1 to 120 minutes, using the removing solution of the invention. Thetreatment time generally varies according to treatment method, and isdetermined by the effects of equipment and treatment solution. Forexample, with single-wafer processing equipment, it is no more than 10minutes, and with batch processing equipment, it is no more than 60minutes. The removing solution of the present invention can be used witha wide range of treatment times from 0.1 to 120 minutes.

If the etching amount of an insulating film barrier and low-k film issmall, it becomes difficult to remove etching residue. If the etchingamount thereof is large, the resulting pattern becomes larger than it isdesigned to be, thus causing problems. The ratio of the etching amountof the insulating film barrier to that of the low-k film is preferablyat least 0.3, and is more preferably at least 1.0. If the etching amountratio is low, the low-k film is more deeply etched than the insulatingfilm barrier, causing differences in level at the interface between theinsulating film barrier and the low-k film. When embedding a barriermetal or embedding wiring copper, the differences in level conceal thelow-k film behind the insulating film barrier, causing imperfectembedding.

When a nitrogen-containing gas or an etching gas mixed with nitrogen isused as the etching gas for dry etching silicon (Si)-containing low-kfilm, the silicon in the low-k film and nitrogen react together to forma compound having a Si—N bond which is similar to silicon nitride (SiN)in composition, giving an etching residue containing this compound.Similarly, when a nitrogen-containing gas is used for the ashing ofetching residue, silicon in the low-k film and nitrogen react togetherto form a compound having a Si—N bond which is similar to siliconnitride (SiN) in composition. The hydrogen fluoride-containing removingsolution according to the present invention can remove etching residuehaving this Si—N bond selectively and effectively. Moreover, theremoving solution can also selectively remove etching residue remainingafter the ashing process in which a plasma treatment is conducted toremove part of the residue after etching by ashing, reaction, etc.Plasmas such as oxygen, hydrogen, nitrogen, helium, argon, neon,krypton, xenon, and other noble gases; water; and alcohols are used insuch plasma treatments.

The organic acid or organic solvent in the invention is at least onemember selected from the group consisting of polar aprotic solventshaving a donor number of no more than 24, neutral solvents, andprotogenic solvents. Neutral solvents and protogenic solvents areclassified as amphiprotic solvents, while polar aprotic solvents havinga donor number of no more than 24 are generally classified as aproticsolvents. Aprotic solvents that have a comparatively high dipole momentand dielectric constant are referred to as polar aprotic solvents, andother aprotic solvents which have a very low dipole moment anddielectric constant and have very low acidity and basicity are referredto as inert solvents. Polar aprotic solvents can be further classifiedinto polar protophilic solvents and polar protophobic solvents. Polarprotophilic solvents have higher basicity than water, and polarprotophobic solvents have lower basicity than water.

Preferable neutral solvents are alcohols; preferable protogenic solventsare monocarboxylic acids, polycarboxylic acids, and sulfonic acids; andpreferable polar aprotic solvents having a donor number of no more than24 are esters, ethers, ketones, and acid anhydrides.

(I) As neutral solvents, (1) the alcohols are at least one memberselected from the group consisting of methyl alcohol, ethyl alcohol,propanol, isopropanol, t-butanol, allyl alcohol, ethylene glycol,propylene glycol, ethylene glycol monomethyl ether, ethylene glycolmonoethyl ether, ethylene glycol monopropyl ether, ethylene glycolmonoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycolmonoisobutyl ether, diethylene glycol monomethyl ether, diethyleneglycol monoethyl ether, diethylene glycol monopropyl ether, diethyleneglycol monoisopropyl ether, diethylene glycol monobutyl ether,diethylene glycol monoisobutyl ether, triethylene glycol monomethylether, triethylene glycol monoethyl ether, triethylene glycol monopropylether, triethylene glycol monoisopropyl ether, triethylene glycolmonobutyl ether, triethylene glycol monoisobutyl ether, polyethyleneglycol monomethyl ether, propylene glycol monomethyl ether, propyleneglycol monoethyl ether, propylene glycol monopropyl ether, propyleneglycol monoisopropyl ether, propylene glycol monoisobutyl ether,propylene glycol monobutyl ether, dipropylene glycol monomethyl ether,dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether,dipropylene glycol monoisopropyl ether, tripropylene glycol monomethylether, and ethylene glycol monoallyl ether (methyl alcohol and ethylalcohol not being used singly, but being used in combination with othersolvent(s)).

(II) As protogenic solvents, (1) the monocarboxylic acids are at leastone member selected from the group consisting of formic acid, aceticacid, propionic acid, butyric acid, isobutyric acid, monochloroaceticacid, dichloroacetic acid, trichloroacetic acid, monofluoroacetic acid,difluoroacetic acid, trifluoroacetic acid, α-chlorobutyric acid,β-chlorobutyric acid, γ-chlorobutyric acid, lactic acid, glycolic acid,pyruvic acid, glyoxalic acid, methacrylic acid, and acrylic acid; (2)the polycarboxylic acids are at least one member selected from the groupconsisting of oxalic acid, succinic acid, adipic acid, and citric acid;and (3) the sulfonic acids are at least one member selected from thegroup consisting of methanesulfonic acid, benzenesulfonic acid,toluenesulfonic acid, and trifluoromethanesulfonic acid;

(III) As polar aprotic solvents having a donor number of no more than24, (1) the esters are at least one member selected from the groupconsisting of methyl acetate, ethyl acetate, butyl acetate, propylenecarbonate, ethylene carbonate, ethylene sulfite, lactone, tributylphosphate, and trimethyl phosphate; (2) the ethers are at least onemember selected from the group consisting of dioxane, trioxane, diglyme,1,2-dimethoxyethane, tetrahydrofuran, diethyl ether, dimethoxymethane,dimethoxypropane, diethoxymethane, 1,1-dimethoxyethane, ethylene glycolmethyl ethyl ether, ethylene glycol diethyl ether, diethylene glycoldimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycoldiethyl ether, triethylene glycol dimethyl ether, triethylene glycolethyl methyl ether, triethylene glycol diethyl ether, tetraethyleneglycol dimethyl ether, tetraethylene glycol diethyl ether, polyethyleneglycol dimethyl ether, ethylene glycol monomethyl ether acetate,ethylene glycol monoethyl ether acetate, diethylene glycol monomethylether acetate, and diethylene glycol monoethyl ether acetate; (3) theketones are acetone; and (4) the acid anhydrides are acetic anhydride.

When large amounts of organic substances are present in etching residuesincluding resist, antireflection coatings, and filling materials, asolvent with which the organic components can be easily dissolved ispreferable. Of the alcohols, for example, ethanol is more preferablethan methanol, and isopropanol is even more preferable than ethanol.

Of the polar aprotic solvents having a donor number of no more than 24,neutral solvents, and protogenic solvents, preferable are carboxylicacids, alcohols, esters, and ethers. Further, of these, an especiallypreferable monocarboxylic acid is acetic acid; especially preferablealcohols are isopropanol (IPA), 1-propanol, t-butanol, allyl alcohol,ethylene glycol, ethylene glycol monomethyl ether, ethylene glycolmonoethyl ether, ethylene glycol monopropyl ether, ethylene glycolmonoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycolmonoisobutyl ether, diethylene glycol monomethyl ether, diethyleneglycol monoethyl ether, diethylene glycol monopropyl ether, diethyleneglycol monoisopropyl ether, diethylene glycol monobutyl ether,diethylene glycol monoisobutyl ether, triethylene glycol monomethylether, triethylene glycol monoethyl ether, triethylene glycol monopropylether, triethylene glycol monoisopropyl ether, triethylene glycolmonobutyl ether, triethylene glycol monoisobutyl ether, polyethyleneglycol monomethyl ether, propylene glycol monomethyl ether, propyleneglycol monoethyl ether, propylene glycol monopropyl ether, propyleneglycol monoisopropyl ether, propylene glycol monoisobutyl ether,propylene glycol monobutyl ether, dipropylene glycol monomethyl ether,dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether,dipropylene glycol monoisopropyl ether, tripropylene glycol monomethylether, and ethylene glycol monoallyl ether; especially preferable estersare methyl acetate, ethyl acetate, butyl acetate, propylene carbonate,ethylene carbonate; and especially preferable ethers are1,2-dimethoxyethane, tetrahydrofuran, dioxane, trioxane, diglyme,ethylene glycol methyl ethyl ether, ethylene glycol diethyl ether,diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether,diethylene glycol diethyl ether, triethylene glycol dimethyl ether,triethylene glycol ethyl methyl ether, triethylene glycol diethyl ether,tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether,polyethylene glycol dimethyl ether, ethylene glycol monomethyl etheracetate, ethylene glycol monoethyl ether acetate, diethylene glycolmonomethyl ether acetate, and diethylene glycol monoethyl ether acetate.

In the removing solution comprising HF, an organic solvent and/or anorganic acid, and water, organic solvents that are effective forselectively etching an insulating film barrier, separating etchingresidue from an insulating film barrier or low-k film, and dissolvingsilicon nitride (SiN), etc. contained in the etching residue, areneutral solvents and protogenic solvents, which are amphiproticsolvents; and polar aprotic solvents having a donor number of no morethan 24, which are aprotic solvents. Among neutral solvents andprotogenic solvents, those having a large acceptor number are moreeffective for this purpose. Among polar aprotic solvents, those having asmaller donor number are more effective. Moreover, when theconcentration of HF is increased, such effects can be enhanced.

The corrosion of copper, which is a wiring material, is reduced whenusing an amphiprotic solvent that has a large autoprotolysis constantand a large donor number, and when using an aprotic solvent that has asmall donor number. Solvents that have a large donor number and a largeautoprotolysis constant are, for example, alcohols such as isopropanol(IPA), 1-propanol, and t-butanol. Aprotic solvents that have a smalldonor number are polar aprotic solvents having a donor number of no morethan 24, such as esters, ethers, ketones, and acid anhydrides. Incontrast, when an amphiprotic solvent that has a small autoprotolysisconstant and a small donor number is used or when a polar protophilicsolvent having a donor number of at least 24 is used, copper is readilycorroded. Amphiprotic solvents that have a small autoprotolysis constantand a small donor number are, for example, alcohols such as methanol andethanol. Polar protophilic solvents having a donor number of at least 24are, for example, amides such as dimethylformamide, andsulfur-containing compounds such as dimethyl sulfoxide.

The amount of copper corrosion is also related to the speed of removinga native copper oxide film. When the removal of a native copper oxidefilm is fast, the oxide film as a protective film is diminished, so thatthe amount of copper corrosion is increased. Native copper oxide filmshave to be removed at some stage in the production of semiconductordevices. It is desirable to remove the native copper oxide films at thesame time as resist, antireflection coatings, filling materials, andetching residue, using a removing solution. There is correlation betweenthe above-mentioned copper corrosivity and the removal of native copperoxide film. A solvent that readily corrodes copper easily removes anative oxide film. Therefore, by adding a solvent that readily corrodescopper to one that does not, the removal of a native oxide film can becompleted within the time for removal treatment. The speed of removingnative copper oxide film can be controlled by, for example, adding anappropriate amount of methanol to isopropanol. By adjusting the amountof solvent to remove all of the native copper oxide film within the timefor removal treatment, the removing solution can remove the nativecopper oxide film while removing resist, antireflection coatings,filling materials, and etching residue.

Autoprotolysis is a reaction in which proton transfer occurs betweenamphiprotic solvents, such as neutral solvents and protogenic solvents.These solvents have a low autoprotolysis constant pK_(SH).

Autoprotolysis: SH+SH<=>SH²⁺+S²—(SH: amphiprotic solvent)

Autoprotolysis constant: pK_(SH)=[SH²⁺]*[S²⁻]/[SH]²

Acceptor number A_(N) is a measure proposed by Mayer-Gutmann of acceptorproperty, i.e. a measure of a solvent as a Lewis acid. Taking the³¹P-NMR chemical shift value of (C2F5)3PO dissolved in n-hexane as 0,and the ³¹P-NMR chemical shift value of (C2F5)3PO.SbCl₅ complex in1,2-dichloroethane as 100, A_(N) is defined as the ³¹P-NMR chemicalshift value of (C2F5)3PO dissolved in the pure solvent.A _(N)=100δ(solvent)/[δ((C2F5)3PO.SbCl₅ in1,2-dichloroethane)-δ((C2F5)3PO dissolved in n-hexane)]

Donor number D_(N) is a measure proposed by Gutmann of donor property,i.e. the measure of a solvent as a Lewis base. D_(N) is defined as theabsolute value of the value that expresses the enthalpy of the reactionbetween SbCl₅ (10⁻³ moldm⁻³) in 1,2-dichloroethane and a solvent (10⁻³moldm⁻³) in terms of kcal mol⁻¹.D _(N)=−

H (SbCl₅)/kcal mol⁻¹

Organic solvents have an acceptor number and a donor number based on theabove, even though many of them may not have been reported as measuredvalues. The acceptor and donor properties of an organic solvent can beestimated to some extent. For example, as alkyl groups become larger,acceptor numbers tend to become smaller, as in the following:A_(N)(HOH)=54.8, A_(N)(CH₃OH)=41.3, A_(N)(C₂H₅OH)=37.1, A_(N)(C₃H₇OH)=33.5. The reason for this may be that a larger alkyl groupprovides a greater electron-donating I effect (Inductive Effect),increasing the electron density of the H in the hydroxy group —OH, andweakening the electron-accepting property. The A_(N) of C4H9OH, althoughnot reported, can be estimated to be 24 or more, based onA_(N)(CHCl₃)=23.1. In this manner, by comparison with a substance whosedonor number and acceptor number are known, the donor and acceptorproperties of another substance can be estimated in consideration of thechange in the electron density of the atom that exhibits the donor andacceptor properties; and measured values such as those reported in theliterature are not necessary. In an organic solvent, a strong acceptorproperty means high Lewis acidity.

Generally, solvents with an acceptor number of 20 or more areamphiprotic solvents, which are classified into neutral, protogenic, andprotophilic solvents. Frequent transfer of a proton, i.e. a hydrogenion, promotes etching in which hydrogen ions are involved.

In an organic solvent, a strong donor property means high Lewisbasicity. In other words, a weak donor property means low Lewisbasicity; therefore, as when the acceptor number is large, etching inwhich hydrogen ions are involved is promoted.

Hydrogen ions are deeply involved in the etching of silicon(Si)-containing compounds such as silicon nitride (SiN), silicon carbide(SiC), and silicon carbide nitride (SiCN), which are used as insulatingfilm barriers. For the above-mentioned reasons, silicon (Si)-containingcompounds such as SiN, SiC, and SiCN can be more easily etched thanother silicon (Si)-containing compounds such as a low dielectricconstant film (low-k film, which may be expressed in terms of itscomponents such as SiOC and SiOC:H) containing silicon oxide (SiO₂) usedas low-k film; silicon oxide (SiO2), which may be called BPSG, dopedwith phosphorus (P), arsenic (As), antimony (Sb), boron (B), etc.;organic components such as methyl groups (—CH₃); hydrogen; etc.Therefore, etching residue can be removed without etching the low-k filmmore than is necessary. There arise very few differences in level thatconceal the low-k film behind the insulating film barrier, and theremoval of residue causes little damage.

Furthermore, when at least one of the above organic acids and organicsolvents is used, polar protophilic solvents having a donor number of atleast 25, acids, fluorine-containing organic compounds, etc. may beadded.

The addition of a polar protophilic solvent having a donor number of atleast 25 reduces the capability for removing antireflection coatings andfilling materials; however, it provides the effect of increasing thespeed of removal of oxide films formed on wiring copper. If any copperoxide film remains, it may cause insulation failure. Therefore, copperoxide films as well as antireflection coatings and filling materials canbe effectively removed. Examples of polar protophilic solvents having adonor number of at least 25 include amides such as dimethylformamide,dimethylacetamide, hexamethylphosphoric triamide,N-methyl-2-pyrrolidone, 1,1,3,3-tetramethylurea, N-methylpropionamide,and dimethyl imidazolidinone; and sulfur compounds such as dimethylsulfoxide, sulfolane, dimethylthioformamide, N-methylthiopyrrolidone,dimethyl sulfone, diethyl sulfone, bis(2-hydroxyethyl)sulfone, andtetramethylene sulfone.

With the addition of an acid, the effects of hydrogen ions enable moreselective removal of antireflection coatings and filling materials overlow-k film and stopper film. Such acids are, for example, hydrogenchloride, hydrogen bromide, hydrogen iodide, and aqueous solutionsthereof; sulfuric acid, nitric acid, phosphoric acid, and carboxylicacid.

The addition of a fluorine-containing organic compound enhances thepermeability of the removal solution for antireflection coatings andfilling materials. It becomes easy for the solution to permeate theinterface between an antireflection coating or a filling material andother materials such as low-k film and stopper film, and as a result,its removing properties are enhanced. Examples of fluorine-containingorganic compounds include hydrofluoroethers (HFE) such as CHF2CF2OCH2CF3and CHF2CF2OCH3; and hydrochlorofluorocarbons (HCFC) such as CH3CCl2F.

It is desirable for the removing solution/cleaning solution of thepresent invention to contain hydrogen fluoride or a combination ofhydrogen fluoride with ammonia and/or amines as a source for generatingetching species. The etching species herein are active species effectivefor etching, such as active species that etch an insulating film barrierand low-k film or active species for dissolving a compound that has aSi—N bond in etching residue. When the etching residue contains organiccomponents, it is preferable to use a large amount of organic acid andorganic solvent to enhance the solubility of the residue. Hydrogenfluoride may be introduced as a gas, or may be added as 100% hydrogenfluoride liquid or as hydrofluoric acid (hydrogen fluoride diluted withwater). Similarly, ammonia and amines may be added as gases or liquids.

However, when adding hydrogen fluoride, and ammonia and/or amines to asolution with a high content of organic solvent, it is undesirable topreviously mix ammonia and/or amines with hydrogen fluoride, generatingsalts. This makes it difficult to dissolve them in the organic solvent.Usually, either hydrogen fluoride or ammonia and/or amines arepreviously added to an organic solvent, sufficiently mixed, and then theother is added thereto. Such a method can prevent the generation andcrystallization of salts from the solution, and can dissolve them not ascompletely dissociated ions in an electrolytic solution of salts but assolvated ion pairs. One ion in the ion pair functions as an etchingspecies.

The amount of hydrogen fluoride in the removing solution and thecleaning solution of the present invention is determined based on thedesired effect of removing etching residue in consideration of theetching amount of an insulating film barrier and low-k film, and also ofthe etching amount of etching residue having Si—N bonds. Although dilutehydrofluoric acid (50 wt. % aqueous solution) is usually used to supplyhydrogen fluoride, 100% hydrogen fluoride can also be used when theremoving solution does not contain water. The amount of hydrogenfluoride is in the range of 0% to 10% by weight, based on the totalamount of the removing solution/cleaning solution (hereinafter, theamount of each component is indicated based on the total amount of theremoving solution/cleaning solution).

When only protogenic solvents are used in the removing solution/cleaningsolution, the amount of hydrogen fluoride is about 0.05% to about 5% byweight, preferably about 0.1% to about 3% by weight, and more preferablyabout 0.5% to 3% by weight.

When the removing solution/cleaning solution contains a protogenicsolvent, and a polar aprotic solvent having a donor number of no morethan 24 and/or a neutral solvent, the amount of hydrogen fluoride isabout 0.05% to about 10% by weight, preferably about 0.1% to about 5% byweight, and more preferably about 0.5% to 5% by weight.

When the removing solution/cleaning solution contains a neutral solventand/or a polar aprotic solvent, the amount of hydrogen fluoride is about0.1% to about 10% by weight, preferably about 0.5% to about 7% byweight, and more preferably about 1% to about 5% by weight.

When the removing solution/cleaning solution contains water, the amountof water is no more than about 90 mass %, preferably no more than about10 mass %, and more preferably no more than about 5%.

The amount of said at least one member selected from the groupconsisting of polar aprotic solvents having a donor number of no morethan 24, neutral solvents, and protogenic solvents is about 25 to about99.99 mass %, preferably about 50 to about 99.99 mass %, more preferablyabout 85 to about 99.99 mass %, and even more preferably about 95 toabout 99.99 mass %.

Preferable examples of removing solutions, cleaning solutions, andamounts of components in the present invention are given below.

HF/protogenic solvent/water=0.05-5 mass %/89.95-99.95 mass %/0-10 mass %

HF/polar aprotic solvent having a donor number of no more than24/water=0.5-5 mass %/89.5-99.5 mass %/0-10 mass %

HF/neutral solvent/water=0.5-5 mass %/89.5-99.5 mass %/0-10 mass %

The following are more preferable examples of removing solutions,cleaning solutions, and amounts of components in the invention.

HF/acetic acid/water=0.05-5 mass %/85-99.95 mass %/0-10 mass %

HF/isopropanol/water=0.5-5 mass %/85-99.5 mass %/0-10 mass %

HF/acetic acid/IPA/water=0.1-5 mass %/1-98.9 mass %/1-98.9 mass %/0-10mass %

HF/methanol/isopropanol/water 0.1-5 mass %/1-80 mass %/1-98.9 mass%/0-10 mass %

HF/1,2-dimethoxyethane/water=0.5-5 mass %/85-99.5 mass %/0-10 mass %

HF/at least one member selected from the group consisting of methylacetate, ethyl acetate and butyl acetate/water=0.5-5 mass %/85-99.5 mass%/0-10 mass %

HF/1,4-dioxane/water=0.5-5 mass %/85-99.5 mass %/0-10 mass %

HF/propylene carbonate/water=0.5-5 mass %/85-99.5 mass %/0-10 mass %

HF/1,4-dioxane and at least one member selected from the groupconsisting of acetic acid and acetic anhydride/water=0.1-5 mass%/85-99.9 mass %/0-10 mass %

HF/ethylene glycol monomethyl ether/water=0.5-5 mass %/85-99.5 mass%/0-10 mass %

HF/methanesulfonic acid/water=0.001-5 mass %/85-99.999 mass %/0-10 mass%

The following are even more preferable examples of removing solutions,cleaning solutions, and amounts of components in the invention.

HF/acetic acid/water=0.1-5 mass %/85-99.88 mass %/0.02-10 mass %

HF/IPA/water=1-4 mass %/88-98.5 mass %/0.5-8 mass %

HF/acetic acid/IPA/water=0.1-5 mass %/1-98.85 mass %/1-98.85 mass%/0.05-10 mass %

HF/methanol/IPA/water=0.1-5 mass %/1-80 mass %/1-98.85 mass %/0.05-10mass %

HF/1,2-dimethoxyethane/water=0.5-5 mass %/85-99.3 mass %/0.2-10 mass %

HF/at least one member selected from the group consisting of methylacetate, ethyl acetate and butyl acetate/water=0.5-5 mass %/85-99.3 mass%/0.2-10 mass %

HF/1,4-dioxane/water=0.5-5 mass %/85-99.3 mass %/0.2-10 mass %

HF/propylene carbonate/water=0.5-5 mass %/85-99.3 mass %/0.2-10 mass %HF/1,4-dioxane and at least one member selected from the groupconsisting of acetic acid and acetic anhydride/water=0.1-5 mass%/85-99.9 mass %/0-10 mass %

HF/ethylene glycol monomethyl ether/water=0.5-5 mass %/85-99.3 mass%/0.2-10 mass %

HF/methanesulfonic acid/water=0.001-5 mass %/85-99.998 mass %/0.001-10mass %

To the above solutions may be added ammonia and/or amines, polarprotophilic solvents having a donor number of at least 25, acids,fluorine-containing organic compounds, etc. The weight ratio of HF(hydrogen fluoride)/ammonia and/or amine/at least one organic acidand/or organic solvent/water/acid/polar protophilic solvent having adonor number of at least 25/fluorine-containing organic compound ispreferably in the range of 0.05-5 mass %/0.05-10 mass %/50-99.83 mass%/0.02-10 mass %/0.05-50 mass %/0-70 mass %.

Furthermore, in the removal of etching residues, antireflection coatingsand filling materials can be removed separately from or simultaneouslywith low-k film damaged by dry etching and by subsequent plasma ashingwith oxygen, hydrogen, nitrogen, noble gas, etc. (removal of resist andpolymers by a plasma process). Depending on the chemical composition ofthe solution, it is also possible to remove antireflection coatings andfilling materials without removing damaged low-k film.

In wiring materials such as copper and copper alloys, corrosion isaccelerated when a removing solution contains a large amount ofdissolved oxygen, hydrogen ions, etc. In particular, the amount ofdissolved oxygen is an important factor in controlling copper corrosion.If the amount of dissolved oxygen in a removing solution can be reduced,copper corrosion can be greatly inhibited. In this manner, when a metalsuch as wiring copper is present, corrosion can be inhibited by using aremoving solution wherein one or more inert gases are dissolved suchthat the oxygen partial pressure of the solution is below the oxygenpartial pressure in air-saturated solution, under an atmosphere(substantially in inert gas) wherein one or more inert gases are mixedsuch that the atmosphere has an oxygen partial pressure below the oxygenpartial pressure in air, for removing resist, antireflection coatings,and etching residues including these. In this case, rinsing off theremoving solution by the use of water wherein one or more inert gasesare dissolved such that the oxygen partial pressure in the water isbelow the oxygen partial pressure in air-saturated solution is furthereffective in that corrosion in the rinsing process can also beinhibited. Examples of inert gases include noble gases such as nitrogen(N2), helium, neon, and argon. Furthermore, usable additives are, forexample, deoxidizers such as sulfurous acid and sulfites (such asammonium sulfite); and generally used anticorrosives such as pyrogallol,phthalic acid, benzotriazol, and D-sorbitol. These are effective for theinhibition of copper corrosion.

The present invention provides a resist-removing solution that can beused to remove resist without damaging low-k film. The invention alsoprovides a cleaning solution for removing titanium compounds remainingin via holes, capacitors, etc.; and a cleaning solution for via holes,capacitors, etc. that can be used to remove titanium compounds, etc.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention is described below in more detail with referenceto Examples. However, the present invention is not limited to theseexamples.

The etching amounts shown below were obtained by etching each film at23° C. using each composition and calculating the difference in filmthickness between before and after etching.

The SiN film etching rates below were obtained by measuring filmthickness before and after etching, using a “NanoSpec 3000 AF-T”(product of Nanometrics Japan Ltd.). The metal [TiN film] etching rateswere obtained by measuring resistivity before and after etching, using aresistivity meter “K-705RS” (product of Kyowariken, Inc.), andcalculating film thickness based on the measured resistivity.

Resist removability and cross-sectional profile were observed bymicrography using a scanning electron microscope “S-5000” (product ofHitachi, Ltd.).

TEST EXAMPLE 1 Resist Removability

A Si substrate, with a low-k film (porous MSQ), a SiN film, anantireflection coating (BARC), and a resist (KrF) film formed over it,was subjected to etching, giving an object to be treated that had resist(including resist surface modified by etching) on the surface of the SiNfilm.

Each such object was immersed in one of the removing solutions shownbelow in Tables 1 to 4 at 23° C., with stirring for a predeterminedperiod of time. The SP values of the organic acids and organic solventsthat were used are as follows:

acetic acid: 10.1

hexanol: 10.7

lauryl alcohol: 9.8

propylene glycol: 12.6

diethylene glycol: 12.1

glycerin: 16.5

IPA: 11.5

Light O₂ plasma ashing was conducted by carrying out O₂ plasma ashingfor a shorter time than usual such that the low-k film was substantiallynot damaged.

In the “resist removability” columns of the tables, “A,” “B,” and “C”mean excellent, good, and poor, respectively. TABLE 1 Components (mass%) Immersion Light Etching amount Acetic time O₂ plasma Resist of SiN HFWater acid (min) ashing removability film (Å) Ex. 1 0.05 0.05 99.9 30Not conducted A 39 Ex. 2 0.05 0.05 99.9 40 Not conducted A 52 Ex. 3 0.10.1 99.8 20 Not conducted A 56 Ex. 4 0.15 0.15 99.7 15 Not conducted A51 Ex. 5 0.2 0.2 99.6 3 Not conducted A 15 Ex. 6 0.2 0.2 99.6 6 Notconducted A 30 Ex. 7 0.25 0.25 99.5 5 Not conducted A 35 Ex. 8 0.25 0.2599.5 10 Not conducted A 62 Ex. 9 04 04 99.2 10 Not conducted A 60 Ex. 100.5 0.5 99.0 10 Not conducted A 75 Ex. 11 0.75 0.75 98.5 0.5 Notconducted A 10 Ex. 12 0.75 0.75 98.5 1 Not conducted A 20 Ex. 13 0.750.75 98.5 3 Not conducted A 60 Ex. 14 0.05 0.05 99.9 15 Conducted A 20Ex. 15 0.05 0.05 99.9 25 Conducted A 53 Ex. 16 0.1 0.1 99.8 20 ConductedA 56 Ex. 17 0.15 0.15 99.7 15 Conducted A 51 Ex. 18 0.2 0.2 99.6 10Conducted A 47 Ex. 19 0.25 0.25 99.5 3 Conducted A 21 Ex. 20 0.25 0.2599.5 5 Conducted A 35 Ex. 21 0.25 0.25 99.5 10 Conducted A 62 Ex. 22 0.40.4 99.2 10 Conducted A 60 Ex. 23 0.5 0.5 99.0 10 Conducted A 75 Ex. 240.75 0.75 98.5 0.5 Conducted A 10 Ex. 25 0.75 0.75 98.5 1 Conducted A 20Ex. 26 0.75 0.75 98.5 3 Conducted A 60

TABLE 2 Etching Immersion Light amount time O₂ plasma Resist of SiNComponents (min) ashing removability film (Å) Ex. 27 1 mass % HF + 1mass % H₂O + 10 Not A 251 hexanol conducted Ex. 28 0.4 mass % HF + 0.4mass % H₂O + 10 Not A 283 lauryl alcohol conducted Ex. 29 1.5 mass %HF + 1.5 mass % H₂O + 5 Not A 22 propylene glycol conducted Ex. 29 1.5mass % HF + 1.5 mass % H₂O + 10 Not A 48 propylene glycol conducted Ex.30 1.5 mass % HF + 1.5 mass % H₂O + 15 Not A 72 propylene glycolconducted Ex. 31 2.5 mass % HF + 2.5 mass % H₂O + 10 Not A 203 propyleneglycol conducted Ex. 32 1.5 mass % HF + 1.5 mass % H₂O + 10 Not A 180ethylene glycol conducted Ex. 33 2 mass % HF + 2 mass % H₂O + 7.5 Not A40 diethylene glycol conducted Ex. 34 2 mass % HF + 2 mass % H₂O + 10Not A 87 diethylene glycol conducted Ex. 35 3 mass % HF + 3 mass % H₂O +glycerin 10 Not A 480 conducted Ex. 36 1.5 mass % HF + 1.5 mass % H₂O +IPA 10 Not A 41 conducted Ex. 37 1.5 mass % HF + 1.5 mass % H₂O + IPA 15Not A 62 conducted Ex. 38 1 mass % HF + 1 mass % H₂O + 10 Conducted A251 hexanol Ex. 39 0.4 mass % HF + 0.4 mass % H₂O + 10 Conducted A 283lauryl alcohol Ex. 40 2.5 mass % HF + 2.5 mass % H₂O + 10 Conducted A203 propylene glycol Ex. 41 1.5 mass % HF + 1.5 mass % H₂O + 10Conducted A 180 ethylene glycol Ex. 42 2 mass % HF + 2 mass % H₂O + 10Conducted A 40 diethylene glycol Ex. 43 3 mass % HF + 3 mass % H₂O +glycerin 10 Conducted A 480* In Table 2, the amount of the component that is not HF

or H₂O is the balance obtained by subtracting the amounts of HF and H₂Ofrom the total amount. TABLE 3 Components (mass %) Immersion LightResist Acetic time O₂ plasma remov- NH₄F Water Acid (min) ashing abilityComp. 0 0 100 10 Not conducted C Ex. 1 Comp. 0 0 100 10 Conducted C Ex.2

TABLE 4 Immersion Light Time O₂ plasma Resist Component (min) ashingremovability Comp. IPA 10 Not conducted C Ex. 3 Comp. IPA 10 Conducted CEx. 4** In Table 4, concentration is expressed as the number of moles per kgof the total composition.

The resist was completely removed from the substrates treated with theremoving solutions of Examples 1 to 46. The antireflection coating wasalso removed. In all these substrates, the SiN film with antireflectioncoating adhering thereto was etched to a depth of at least 1 Å. On theother hand, the resist was not removed in the substrates treated withthe solutions of Comparative Examples 1 to 3.

TEST EXAMPLE 2 Cross-Sectional Profile

The vertical cross-section of each treated substrate was observed by SEMin comparison with that of the untreated substrate to check the effectsof the removing solutions on low-k film in Examples 1, 5, 6, 7, 11, 12,14, 15, 19, 20, 24, 25, 29, 30, 33, 34, 36, 37, and 42.

The profile of the substrate was substantially unchanged before andafter the treatment with the removing solutions in Examples 1, 5, 6, 7,11, 12, 14, 15, 19, 20, 24, 25, 29, 30, 33, 34, 36, 37, and 42. It wasthus confirmed that the low-k film was not damaged.

The removing solution of the present invention was found to be capableof removing resist without substantially damaging low-k film.

COMPARATIVE EXAMPLE 4

HF/H₂O=15 Mass %/85 Mass % (23° C.; 10 Minutes; Light O₂ Plasma AshingConducted or Not Conducted)

In Comparative Example 4, although it was possible to remove the resist,the low-k film was damaged, being removed together with the resist.

TEST EXAMPLE 3 Polymer/Titanium Compound Removability

A resist film was formed over a Si wafer having an oxide film with anunderlying TiN film, subjected to dry etching and O₂ plasma ashing, thusgiving an object to be treated that had via holes. Polymers and titaniumcompounds remained on the sidewalls and the bottoms of the via holes.

The object was immersed in the following cleaning solution (Example 44)with stirring at 23° C. for a predetermined period of time.

EXAMPLE 44 HF/H₂O/Acetic Acid=0.75 Mass %/0.75 Mass %/98.5 Mass % (10Minutes)

The treatment with the cleaning solution of Example 44 removed thepolymers and titanium compounds remaining in the via holes, thuscleaning the via holes. The TiN film was etched to a depth of 2.4 Å.

TEST EXAMPLE 4 Resist Residue Removability Test

A resist film was formed over a Si wafer having TiN (upper layer)/Ta₂O₅(lower layer) with an underlying silicon oxide film, subjected to dryetching of TiN (upper layer)/Ta₂O₅ (lower layer) and O₂ plasma ashing,thus giving an object to be treated that had metal capacitor electrodes.Resist residue remained on the surface of the electrodes.

Each such object was immersed in one of the following cleaning solutions(Examples 45 and 46) with stirring at 23° C. for a predetermined periodof time.

EXAMPLE 45 HF/H₂O/Acetic Acid=1.5 Mass %/1.5 Mass %/97 Mass % (10Minutes) EXAMPLE 46 HF/H₂O/Acetic Acid=3 Mass %/3 Mass %/96 Mass % (10Minutes)

The treatments with the cleaning solutions of Example 45 and 46 removedthe resist residue remaining on the surface of the metal capacitorelectrodes, thus cleaning the capacitors. The TiN film was etched to adepth of 6.2 Å in Example 45, and to a depth of 12 Å in Example 46.

If resist residue on the surface of capacitor electrodes can be removed,and polymers and titanium compounds remaining in via holes can beremoved, then it is expected that polymers and titanium compounds on thesurface of capacitor electrodes can also be removed.

EXAMPLES 47 TO 50

A Si substrate with a low-k film [CVD] and a resist film [KrF] formedthereover was subjected to etching, giving an object to be treated thathad resist (including resist modified by etching) on the surface of thelow-k film and had polymers in the resulting holes. Ashing of the resistwas not performed.

The removing solutions of Examples 47 to 50 were prepared, using thecomponents shown below. Each object to be treated was immersed in one ofthe removing solutions, and cleaning was performed with ultrasonicirradiation [950 kHz, 600 W] for the lengths of time shown in Table 5.The equipment used for ultrasonic cleaning was a “HI MEGASONIC”high-frequency ultrasonic cleaning system (generator: model 6848;vibrator: model 7857S) produced by Kaijo Corporation.

The resist was completely removed from the substrates treated with theremoving solutions of Examples 47 to 50. The polymers were also removed.

Removing solutions containing hydrofluoric acid and amine were preparedusing the organic solvents shown in Table 6 below, and ultrasoniccleaning was performed. It was possible to remove the resist and thepolymers.

Since the above test example confirmed that the compositions shown inTables 5 and 6 remove polymers in via holes, the compositions areexpected to be capable of removing titanium compounds remaining in viaholes. These compositions are also expected to be capable of removingresist residue, polymers, and titanium compounds on the surface ofcapacitor electrodes. TABLE 5 Ultrasonic Irradiation Resist Solvent HFAmine time Removability Polyhydric Ex. 47 Ethylene glycol 1Monoethanolamine 10 min A alcohol mol/kg 0.5 mol/kg Amide Ex. 48 N,N-0.02 Monoethanolamine 20 min A dimethylformamide mol/kg 0.01 mol/kg Ex.49 N,N- 0.02 Ethylamine 20 min A dimethylformamide mol/kg 0.01 mol/kgEx. 50 N-methylformamide 0.5 Monoethanolamine 10 min A mol/kg 0.25mol/kg

TABLE 6 Solvent Ester Ex. 51 Butyl acetate Ex. 52 Dimethyl phthalate Ex.53 Propylene carbonate Ketone Ex. 54 Methyl isobutyl ketone Ex. 55Cyclohexanone Alcohol Ex. 56 1-dodecanol Ex. 57 1-hexanol Ex. 581-butanol Ex. 59 Isopropyl alcohol Ex. 60 1-propanol Polyhydric alcoholEx. 61 Propylene glycol Nitrogen-containing compound Ex. 62N-methyl-2-pyrrolidone Ex. 63 Tetramethylurea Phosphate ester Ex. 64Trimethyl phosphate Ex. 65 Triethyl phosphate Alkylene glycol monoalkylether Ex. 66 2-ethoxyethanol

EXAMPLE 5 Resist Removability

A Si substrate with a porous low-k film (porous MSQ), a SiC film, asilicon-containing antireflection coating (BARC), and a resist (KrF)film formed thereover was subjected to via etching, giving an object tobe treated with a damascene structure before the formation of copperwiring, the object having the resist (including resist surface modifiedby etching) and antireflection coating on the surface of the SiN film,and having etching residue in via holes. Each such object was immersedin one of the cleaning solutions shown in Table 7 at 23° C. withstirring for a predetermined period of time.

EXAMPLES 67 TO 83

In Examples 67 to 83, after producing the above object to be treated,plasma treatment such as oxygen ashing was not performed for removingthe resist, antireflection coating, and etching residue. When theremoving solutions of Examples 67 to 83 shown in Table 7 were used, inthe treatment time, SiC was etched to a depth of at least 1 Å, and SiNwas etched to a depth of at least 12 Å. The resist, antireflectioncoating, and etching residue were all completely removed from thesubstrates that were treated with these removing solutions. Solventsthat are effective for etching SiN, i.e., for dissolving etching residuecontaining silicon nitrides such as SiN are, as shown here, amphiproticsolvents such as neutral solvents (methanol, ethanol, isopropanol) andprotogenic solvents (trifluoroacetic acid, acetic acid, formic acid);and aprotic solvents such as polar aprotic solvents having a donornumber of no more than 24 (1,2-dimethoxyethane, tetrahydrofuran, methylacetate, ethyl acetate, 1,4-dioxane, propylene carbonate, and acetone).The examples show that when these solvents are used, the removingsolutions are highly effective for removing resist, antireflectioncoating, and etching residue. These examples confirm that when theconcentration of HF is increased, the removing solution becomes moreeffective for the removal of resist, antireflection coating, and etchingresidue. Moreover, etching of SiC to a depth of at least 1 Å enhancesthe effect of stripping resist, antireflection coating, and etchingresidue at each interface, thus removing them.

When a higher concentration of HF than shown in Example 71 is used incombination with ethanol, copper corrosion occurs. In the other Examplesin Table 7, almost no copper corrosion occurs, therefore causingsubstantially no problems.

On the other hand, the resist, antireflection coating, and etchingresidue were not removed from the substrates treated with the solutionsof Comparative Examples 5 to 9 in Table 8. Etching of SiC to a depth ofat least 1 Å is not sufficient for effectively removing resist,antireflection coating, and etching residue. To remove these, theetching of both SiN and SiC is required. The solutions of ComparativeExamples 5 to 9 readily corrode copper, and when a single solvent suchas shown in the examples is used, they are not suitable as removingsolutions.

Furthermore, Examples 67 to 83 and Comparative Examples 5 to 9 provethat when using an amphiprotic solvent with a large autoprotolysisconstant and a large donor number, and when using an aprotic solventwith a small donor number, the corrosion of copper is reduced. Solventsthat have a large autoprotolysis constant and a large donor number are,for example, among alcohols, isopropanol (IPA), 1-propanol, andt-butanol. Aprotic solvents that have a small donor number are polaraprotic solvents having a donor number of no more than 24, such asesters, ethers, ketones, and acid anhydrides. In contrast, copper isreadily corroded when using an amphiprotic solvent that has a smallautoprotolysis constant and a small donor number, and when using a polarprotophilic solvent having a donor number of at least 24. Amphiproticsolvents that have a small autoprotolysis constant and a small donornumber are, for example, among alcohols, methanol, ethanol, etc. Polarprotophilic solvents having a donor number of at least 25 are, forexample, amides such as dimethylformamide and sulfur-containingcompounds such as dimethyl sulfoxide.

In Comparative Examples 5 to 9, if the concentration of HF is increased,removability can be somewhat improved; however, it does not bring aboutany great effect. Also, in those portions where copper wiring isexposed, the corrosion of copper is accelerated, making the use of suchsolutions difficult. However, the organic solvents used in ComparativeExamples 5 to 9 are effective for removing native copper oxide films. Itis desirable to remove native copper oxide films because these increasewiring resistance and may cause poor contact. The organic solvents usedin Comparative Examples 5 to 9 can be mixed into the solutions ofExamples 67 to 83 to remove only the native oxide films of copper whileremoving resist, antireflection coating, and etching residue in a lengthof treatment time that causes little copper corrosion. In Table 9,Comparative Examples 11 and 12 are examples of treatment with chemicalsolutions of typical composition used as polymer removing solutions forforming an Al/SiO2 multilevel interconnection structure. In theseexamples, although there was not much copper corrosion, the resist,antireflection coating, and etching residue were not removed. Iftreatment time is lengthened, removability can be somewhat improved;however, the corrosion of copper is promoted, and the amount of etchedlow-k film is increased, thus making accurate processing difficult.

In addition, the results in the Examples and the Comparative Exampleswere almost the same as those obtained when ashing treatment wasperformed by plasmas such as oxygen plasma, hydrogen plasma, or waterplasma. TABLE 7 Physical properties of Organic solvent Components Auto-Ex. HF Organic acid and Organic solvent Water Acceptor Donor protolysisNo. mass % Kind mass % Kind mass % mass % number number constant 67 0.4Trifluoroacetic 98.2 — — 0.4 105.3 — — acid 68 1.0 Formic acid 96.1 — —1.0 83.6 19.0 6.2 69 0.7 Acetic acid 98.5 — — 0.8 52.9 2.0 14.5 70 0.2Acetic acid 99.6 — — 0.2 52.9 2.0 14.5 71 1.0 Ethanol 97.6 — — 1.0 37.932.0 18.9 72 0.8 Isopropyl alcohol 98.5 — — 0.8 33.6 36.0 20.8 73 0.8Acetone 97.5 — — 0.8 12.5 17.0 >32.5 74 0.5 1,4-dioxane 98.0 — — 0.510.8 14.8 — 75 0.6 Methyl acetate 98.3 — — 0.6 10.7 16.5 — 76 0.5 Ethylacetate 98.5 — — 0.5 9.3 17.1 22.8 77 0.5 1,2- 98.0 — — 0.5 10.2 23.9 —dimethoxyethane 78 2.3 1,2- 94.5 — — 2.3 10.2 23.9 — dimethoxyethane 790.6 Tetrahydrofuran 97.8 — — 0.6 8.0 20.0 — 80 2.0 1,4-dioxane 83.6Acetic 11.4 2.0 11.0 14.8 — anhy- dride 81 2.0 1,4-dioxane 83.6 Acetic22.8 0.0 11.0 14.8 — acid 82 0.6 1,2- 58.9 Acetic 39.3 0.6 32.0 23.9 —dimethoxyethane acid 83 0.6 Triethylene 58.9 — — 0.6 — — — glycoldimethyl ether Etching amount Etching ratio Treatment amount SiN/ Ex.time SiC SiN Low-k Corrosion Removability No. min Å Å film Copper ResistBARC Residue Profile 67 1.0 6.4 31.0 1.3 A A A A A 68 05 2.6 33.1 1.1 AA A A A 69 0.7 3.2 11.5 0.6 A A A A A 70 3.0 2.0 14.1 0.4 A A A A A 717.5 1.0 30.0 0.3 B A A A A 72 7.5 1.8 27.9 0.4 A A A A A 73 10.0 1.024.4 0.3 A A A A A 74 5.0 4.0 22.4 0.8 A A A A A 75 5.0 1.0 22.6 0.4 A AA A A 76 10.0 2.2 55.2 1.1 A A A A A 77 15.0 2.4 30.6 1.0 A A A A A 785.0 1.6 53.2 0.9 A A A A A 79 10.0 2.6 32.0 0.4 A A A A A 80 5.0 1.633.2 1.0 A A A A A 81 5.0 1.6 33.2 1.0 A A A A A 82 10.0 7.0 41.2 0.3 AA A A A 83 5.0 4.3 60.0 1.9 A A A A AA: Excellent,B: Good,C: Poor,—: No evaluation

TABLE 8 Etching Components Physical properties amount Organic of organicsolvent Treat- Etching ratio Corro- Comp. HF solvent Water Auto- mentamount SiN/ sion Removability Ex. mass mass mass Acceptor Donorprotolysis time SiC SiN Low-k Cop- Re- Resi- Pro- No. % Kind % % numberNumber constant min Å Å film per sist BARC dues file 5 0.58 DMSO 97.90.58 19.3 29.9 33.3 5 0.6 3 0.1 C C C C — 6 0.62 DMF 98.3 0.62 16.0 26.629.4 5 1.8 5 0.1 C B B C — 7 0.53 DMA 98.0 0.53 13.6 27.8 23.9 5 1.2 00.0 C B B C — 8 0.46 NMP 98.1 0.46 13.3 27.3 25.6 5 0.0 0 0.0 C C C C —9 0.40 DMI 99.2 0.40 — — — 5 1.4 4 0.1 C B B C — 10 0.50 — — 99.50 — — —5 2.0 650 0.1 C C C C CDMSO (dimethyl sulfoxide),DMF (dimethylformamide),DMA (dimethylacetamide),NMP (N-methylpyrrolidone),DMI(dimethyl imidazolidinone)A: Excellent,B: Good,C: Poor,—: No evaluation

TABLE 9 Physical properties Etching Components of organic solvent amountOrganic Accep- Auto- Treat- Etching ratio Corro- Comp. NH4F solventWater tor proto- ment amount Sin/ sion Removability Ex. mass mass massnum- Donor lysis time SiC SiN Low-k Cop- Re- Resi- Pro- No. % Kind % %ber Number constant min Å Å film per sist BARC dues file 11 0.6 DMF 70.629 19.3 29.9 33.3 5 0 5 0.1 B C C C — 12 0.6 DMSO 69 30.4 16.0 26.6 29.45 0 4 0.1 B C C C —DMSO (dimethyl sulfoxide),DMF (dimethylformamide)A: Excellent,B: Good,C: Poor,—: No evaluation

In Table 10, Comparative Examples 13 to 43 show the results of treatingan object to be treated in the present invention, using thecompositions, etc. for removing solutions or cleaning solutionsdescribed in the examples of other patent applications that have beenfiled. Most of the removing solutions and cleaning solutions shown inthese Comparative Examples were developed for use in the formation of anAl/SiO2 multilevel interconnection structure.

Comparative Examples 13 to 16 show the results of treating an object tobe treated in the present invention, using the composition described inthe examples of Japanese Unexamined Patent Publication No. 1989-146331.The composition is a cleaning solution composed of hydrogen fluoride,isopropanol, and water, wherein the concentration of hydrogen fluorideis 0.5% or less by weight. This cleaning solution cannot selectivelyetch an insulating film barrier or a silicon nitride (SiN) film, so thatit has a poor capability for removing resist, antireflection coating,and etching residue. The results also show that when the cleaningsolution has a high water content, the resist and antireflection coating(BARC), which are organic compositions, cannot be removed, reducingetching residue removability, and that copper is heavily corroded.

Comparative Examples 17 to 19 also show the results of treating anobject to be treated in the present invention, using the compositiondescribed in the examples of Japanese Unexamined Patent Publication No.1989-146331. These are examples in which the cleaning solution, whenusing acetic acid as the organic solvent, has a high or very high watercontent. Since the cleaning solution has a high water content ascompared to HF concentration, it cannot remove resist, antireflectioncoating (BARC), and etching residue. As the content of water increases,the amount of etched SiC decreases, and the amount of etched SiN andlow-k film increases, thus making accurate processing difficult.

Comparative Examples 20 and 21 show the results of treating an object tobe treated in the present invention, using the composition described inthe examples of Japanese Unexamined Patent Publication No. 1996-202052.In Comparative Example 20, since the amount of etched SiC is small,resist and antireflection coating (BARC) cannot be removed. InComparative Example 21, since the effect of selectively etching siliconnitride (SiN) over low-k film is low, the etching residue cannot beremoved. The selective etching ratio of SiN to Low-k film is so low thatif treatment time is lengthened to remove resist, antireflection coating(BARC), and etching residue, the amount of etched low-k film will beincreased, thus making accurate processing difficult. JapaneseUnexamined Patent Publication No. 1996-202052 mentions sulfoxides,amides, polyhydric alcohols, etc. as effective organic solvents.Sulfoxides and amides readily corrode copper, and particularly dimethylsulfoxide, which is mentioned in the examples, heavily corrodes copper.Since anticorrosives are used, it is clear that copper is not intendedas a wiring material. In contrast, the present invention uses organicsolvents that do not require any anticorrosives. It is thus clear thatthe composition disclosed in Japanese Unexamined Patent Publication No.1996-202052 is not suitable as a removing solution used in the formationof a Cu/low-k multilevel interconnection structure.

Comparative Example 22 shows the results of treating an object to betreated in the present invention, using the composition described in theexamples of Japanese Unexamined Patent Publication No. 1998-50647. Thiscomposition can etch SiC and SiN only in small amounts, and cannotremove any of resist, antireflection coating (BARC), and etchingresidue. The selective etching ratio of SiN to the Low-k film is so lowthat if treatment time is lengthened for the removal of resist,antireflection coating (BARC), and etching residue, the amount of etchedlow-k film will be increased, thus making accurate processing difficult.

Comparative Examples 23 to 25 and Comparative Examples 26 show theresults of treating an object to be treated in the present invention,using the compositions described in the examples of U.S. Pat. No.6,150,282 and U.S. Pat. No. 6,150,282, respectively.

In Comparative Examples 23 to 25, when propylene carbonate is used as asolvent, little copper corrosion occurs, and etching residueremovability is not poor. However, the removability for BARC and resistis poor, so that they cannot be completely removed. In addition,processing accuracy is not high.

In Comparative Example 26, the composition contains substantially nowater, causing little metal corrosion. Without water, silicon nitride(SiN) cannot be selectively removed over low-k film; therefore, etchingresidue removability becomes particularly poor. In this case, resist andantireflection coating (BARC) cannot be removed, either.

Comparative Examples 26 to 35 show the results of treating an object tobe treated in the present invention, using the composition described inthe examples of Japanese Unexamined Patent Publication No. 1999-340183.When the concentration of HF is low, the etching rate of SiC and SiN islow, so that resist, antireflection coating (BARC), and etching residuecannot be removed. When the concentration of HF is increased, heavycopper corrosion occurs since methanol is used as a solvent. Therefore,the composition is not suitable as a removing solution used for aCu/low-k multilevel interconnection structure.

Comparative Examples 36 to 41 show the results of treating an object tobe treated in the present invention, using a composition as in theexamples of Japanese Unexamined Patent Publication No. 1999-340183,except that isopropanol (IPA) was used as the organic solvent in placeof methanol. Even with the use of isopropanol, when the concentration ofHF is low or when the concentration of HF is high but the content ofwater is low, resist, antireflection coating (BARC), and etching residuecannot be removed.

Comparative Examples 42 and 43 show the results of using acetic acid asthe organic solvent, with a high concentration of HF and with a lowconcentration of HF, respectively. When HF concentration is low, none ofthe resist, antireflection coating, and etching residue can be removed.When HF concentration is high, all of the resist, antireflectioncoating, and etching residue can be removed; however, stripping occursat the interface between the SiC insulating film barrier and low-k film,promoting the side etching of the low-k film. As a result, the intendedprofile cannot be achieved. TABLE 10 Etching amount Treat- Etching ratioComp. Components ment amount Sin/ Corro- Removability Ex. HF Organicsolvent Water Anticorrosive time SiC SiN Low-k sion Re- Resi- Pro- No.mass % Kind mass % mass % Kind mass % min Å Å film Copper sist BARC duesfile 13 0.3 Isopropanol 16.4 83.3 — — 5.0 0.2 31.0 0.5 C C C C C 14 0.334.3 65.3 — — 5.0 0.3 30.0 0.5 C C C C C 15 0.3 53.9 45.7 — — 5.0 0.328.0 0.5 C C C C C 16 0.3 75.5 24.2 — — 5.0 0.4 25.0 0.4 C C C B C 170.3 Acetic acid 10.7 89.0 — — 2.0 0.4 50.0 0.5 A C C C — 18 0.3 31.568.2 — — 2.0 0.6 35.0 0.5 A C C C — 19 0.3 61.5 38.2 — — 2.0 0.7 25.00.6 A C C B — 20 2.0 Diethylene 86.0 2.0 Catechol 10.0 1.0 0.5 10.0 0.1A C C C C glycol monobutyl ether 21 5.0 Dimethyl 80.0 5.0 Catechol: 5:51.0 2.0 1.0 0.1 A C C C C sulfoxide Salicylic acid 22 0.4 Isopropanol95.6 4.0 — — 5.0 0.5 9.0 0.2 A C C A C 23 0.4 Propylene 99.2 0.4 — — 5.02.6 27.0 0.6 A C B A C 24 0.8 carbonate 98.4 0.8 — — 5.0 3.0 40.0 0.6 AC B A C 25 1.1 97.7 1.1 5.0 3.2 58.0 0.6 A C B A C 26 1.0 99.1 0.0 — —5.0 0.7 8.0 0.2 A C C C C 27 0.1 Methanol 99.9 0.0 — — 5.0 0.4 2.5 0.1 BC C C — 28 0.1 98.9 1.0 — — 5.0 0.4 3.5 0.3 B C C C — 29 0.1 94.9 5.0 —— 5.0 0.4 4.0 0.3 B C C C — 30 1.0 99.0 0.0 — — 5.0 2.0 11.6 0.1 C C C C— 31 1.0 98.0 1.0 — — 5.0 2.0 17.3 3.6 C C C B C 32 1.0 94.0 5.0 — — 5.02.0 23.1 3.7 C C C B C 33 5.0 95.0 0.0 — — 5.0 2.3 8.3 0.2 C C C C C 345.0 94.0 1.0 — — 5.0 2.2 8.6 0.3 C C C A C 35 5.0 90.0 5.0 — — 5.0 2.262.9 4.0 C C C A C 36 0.1 IPA 99.9 0.0 — — 5.0 0.4 0.8 0.1 A C C C — 370.1 98.9 1.0 — — 5.0 0.4 1.2 0.2 A C C C — 38 0.1 94.9 5.0 — — 5.0 0.41.3 0.3 A C C C — 39 1.0 99.0 0.0 — — 5.0 2.2 2.9 0.2 A C C C — 40 5.095.0 0.0 — — 5.0 2.0 3.9 0.3 A C C C — 41 5.0 94.0 1.0 — — 5.0 0.8 21.00.5 A C C C — 42 0.003 Acetic acid 99.994 0.003 — — 2.0 0.0 0.2 0.1 A CC C — 43 8.0 84.0 8.0 — — 2.0 4.2 780.0 0.2 A C A A CA: Excellent,B: Good,C: Poor,—: No evaluation

TEST EXAMPLE 6 Cross-Sectional Profile

The vertical cross-section of each treated substrate was observed by SEMin comparison with that of the untreated substrate to check the effectsof the removing solutions on low-k film in Examples 67 to 83 andComparative Examples 5 to 43. The profile of the substrate wassubstantially unchanged before and after the treatment with the removingsolutions in Examples 67 to 83. It was thus confirmed that the low-kfilm was not damaged.

The removing solution of the present invention was found to be capableof removing resist, antireflection coating, and etching residuesincluding these, without substantially damaging low-k film.

COMPARATIVE EXAMPLE 10

HF/H₂O=0.5 Mass %/99.5 Mass %

In Comparative Example 10, although it was possible to remove the resistand antireflection coating, the low-k film was damaged, being removedtogether with the resist and antireflection coating.

In Comparative Examples 5 to 9, 11, and 12, since the resist,antireflection coating, and etching residues including these were notremoved, no evaluation was made in terms of profile. If treatment timeis lengthened until they have been removed, the amount of etched low-kfilm will be increased. Since accurate processing cannot be performed,as intended, the obtained profile becomes extremely poor.

In Comparative Examples 13 to 43, there were some cases where since theresist, antireflection coating, and etching residues including thesewere not removed, no evaluation was made in terms of profile. In othercases, even when the resist or antireflection coating or etchingresidues including these were removed, the obtained profile wasextremely poor.

1. A resist-removing solution for low-k film comprising hydrogenfluoride (HF) and at least one member selected from the group consistingof organic acids and organic solvents.
 2. A resist-removing solutionaccording to claim 1, further comprising at least one member selectedfrom the group consisting of ammonia and amines.
 3. A removing solutionaccording to claim 1, wherein the solution is used for ultrasoniccleaning.
 4. A removing solution according to claim 1, wherein the low-kfilm has a dielectric constant greater than 1 but not greater than
 3. 5.A removing solution according to claim 1, whereby a SiN film can beetched to a depth of at least 1 Å.
 6. A removing solution according toclaim 1, wherein the organic acids or organic solvents have an SP valueof 7 to
 17. 7. A removing solution according to claim 1, wherein theconcentration of HF is in the range of 0.01 to 10 mass %.
 8. A removingsolution according to claim 1, wherein said at least one member selectedfrom the group consisting of organic acids and organic solvents isorganic acid(s) or a mixture of organic acid(s) and organic solvent(s);and the concentration of HF is in the range of 0.01 to 5 mass %.
 9. Aremoving solution according to claim 1, wherein said at least one memberselected from the group consisting of organic acids and organic solventsis organic solvent(s); and the concentration of HF is in the range of0.01 to 10 mass %.
 10. A removing solution according to claim 1, furthercomprising water, wherein the weight ratio of HF/organic acid/water isin the range of 0.01 to 5 mass %/49 to 99.9 mass %/0 to 50 mass %; andthe organic acid is at least one member selected from the groupconsisting of monocarboxylic acids, sulfonic acids, and polycarboxylicacids.
 11. A removing solution according to claim 10, wherein themonocarboxylic acids are at least one member selected from the groupconsisting of acetic acid, propionic acid, butyric acid, isobutyricacid, valeric acid, caproic acid, caprylic acid, monochloroacetic acid,dichloroacetic acid, trichloroacetic acid, monofluoroacetic acid,difluoroacetic acid, trifluoroacetic acid, α-chlorobutyric acid,β-chlorobutyric acid, γ-chlorobutyric acid, lactic acid, glycolic acid,pyruvic acid, glyoxalic acid, methacrylic acid, and acrylic acid; thesulfonic acids are at least one member selected from the groupconsisting of methanesulfonic acid, benzenesulfonic acid,trifluoromethanesulfonic acid, and toluenesulfonic acid; and thepolycarboxylic acids are at least one member selected from the groupconsisting of oxalic acid, succinic acid, adipic acid, tartaric acid,and citric acid.
 12. A removing solution according to claim 1, furthercomprising water, wherein the weight ratio of HF/organic solvent/wateris in the range of 0.01 to 10 mass %/49 to 99.9 mass %/0 to 50 mass %;and the organic solvent is at least one member selected from the groupconsisting of monohydric alcohols, polyols, ketones, amides, nitriles,aldehydes, alkylene glycol monoalkyl ethers, ethers, esters,hydrocarbons, halogen compounds, fluorinated alcohols, phosphate esters,and nitrogen-containing compounds.
 13. A removing solution according toclaim 2, wherein the weight ratio of HF/said at least one memberselected from the group consisting of ammonia and amines/organicsolvent/water is in the range of 0.01 to 10 mass %/0.01 to 30 mass %/49to 99.9 mass %/0 to 50 mass %; and the organic solvent is at least onemember selected from the group consisting of monohydric alcohols,polyols, ketones, amides, nitriles, aldehydes, alkylene glycol monoalkylethers, ethers, esters, hydrocarbons, halogen compounds, fluorinatedalcohols, phosphate esters, and nitrogen-containing compounds.
 14. Aremoving solution according to claim 12, wherein the monohydric alcoholsare at least one member selected from the group consisting of methanol,ethanol, isopropanol (IPA), 1-propanol, 1-butanol, 2-butanol, t-butanol,2-methyl-1-propanol, 1-pentanol, 1-hexanol, 1-heptanol, 4-heptanol,1-octanol, 1-nonyl alcohol, 1-decanol, 1-dodecanol, lauryl alcohol, andcyclohexanol, with the proviso that methanol and ethanol are used incombination with other organic solvent(s) or organic acid(s); thepolyols are at least one member selected from the group consisting ofethylene glycol, diethylene glycol, 1,2-propanediol, propylene glycol,2,3-butanediol, and glycerin; the ketones are at least one memberselected from the group consisting of acetone, acetylacetone, methylethyl ketone, methyl isobutyl ketone, cyclohexanone, diethyl ketone, anddiisobutyl ketone; the amides are at least one member selected from thegroup consisting of N-methylformamide, N,N-dimethylformamide,N-methylacetamide, and N,N-dimethylacetamide; the nitriles are at leastone member selected from the group consisting of acetonitrile,propionitrile, butyronitrile, isobutyronitrile, and benzonitrile; thealdehydes are at least one member selected from the group consisting offormaldehyde, acetaldehyde, and propionaldehyde; the alkylene glycolmonoalkyl ethers are at least one member selected from the groupconsisting of ethylene glycol monomethyl ether and ethylene glycolmonoethyl ether; the ethers are at least one member selected from thegroup consisting of tetrahydrofuran, dioxane, diisopropyl ether, dibutylether, tetrahydropyran, anisole, 1,2-dimethoxyethane, and diethyleneglycol dimethyl ether; the esters are at least one member selected fromthe group consisting of methyl acetate, ethyl acetate, propyl acetate,isopropyl acetate, butyl acetate, isobutyl acetate, pentyl acetate,hexyl acetate, methyl propionate, ethyl propionate, propyl propionate,isopropyl propionate, butyl propionate, isobutyl propionate, pentylpropionate, hexyl propionate, methyl butyrate, ethyl butyrate, propylbutyrate, isopropyl butyrate, butyl butyrate, isobutyl butyrate, pentylbutyrate, hexyl butyrate, methyl isobutyrate, ethyl isobutyrate, propylisobutyrate, isopropyl isobutyrate, butyl isobutyrate, isobutylisobutyrate, pentyl isobutyrate, hexyl isobutyrate, methyl valerate,ethyl valerate, propyl valerate, isopropyl valerate, butyl valerate,isobutyl valerate, pentyl valerate, hexyl valerate, methyl isovalerate,ethyl-isovalerate, propyl isovalerate, isopropyl isovalerate, butylisovalerate, isobutyl isovalerate, pentyl isovalerate, hexylisovalerate, methyl caproate, ethyl caproate, propyl caproate, isopropylcaproate, butyl caproate, isobutyl caproate, pentyl caproate, hexylcaproate, methyl caprylate, ethyl caprylate, propyl caprylate, isopropylcaprylate, butyl caprylate, isobutyl caprylate, pentyl caprylate, hexylcaprylate, methyl octanoate, ethyl octanoate, propyl octanoate,isopropyl octanoate, butyl octanoate, isobutyl octanoate, pentyloctanoate, hexyl octanoate, methyl nonanoate, ethyl nonanoate, propylnonanoate, isopropyl nonanoate, butyl nonanoate, isobutyl nonanoate,pentyl nonanoate, hexyl nonanoate, methyl decanoate, ethyl decanoate,propyl decanoate, isopropyl decanoate, butyl decanoate, isobutyldecanoate, pentyl decanoate, hexyl decanoate, methyl dodecanoate, ethyldodecanoate, propyl dodecanoate, isopropyl dodecanoate, butyldodecanoate, isobutyl dodecanoate, pentyl dodecanoate, hexyldodecanoate, methyl laurate, ethyl laurate, propyl laurate, isopropyllaurate, butyl laurate, isobutyl laurate, pentyl laurate, hexyl laurate,methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate,butyl acrylate, isobutyl acrylate, pentyl acrylate, hexyl acrylate,monomethyl oxalate, dimethyl oxalate, monoethyl oxalate, diethyloxalate, monopropyl oxalate, dipropyl oxalate, monobutyl oxalate,dibutyl oxalate, monomethyl succinate, dimethyl succinate, monoethylsuccinate, diethyl succinate, monopropyl succinate, dipropyl succinate,monobutyl succinate, dibutyl succinate, monomethyl adipate, dimethyladipate, monoethyl adipate, diethyl adipate, monopropyl adipate,dipropyl adipate, monobutyl adipate, dibutyl adipate, monomethyltartrate, dimethyl tartrate, monoethyl tartrate, diethyl tartrate,monopropyl tartrate, dipropyl tartrate, monobutyl tartrate, dibutyltartrate, monomethyl citrate, dimethyl citrate, monoethyl citrate,diethyl citrate, monopropyl citrate, dipropyl citrate, monobutylcitrate, dibutyl citrate, dimethyl phthalate, diethyl phthalate,dipropyl phthalate, dibutyl phthalate, dipentyl phthalate, dihexylphthalate, diheptyl phthalate, dioctyl phthalate, dinonyl phthalate,didecyl phthalate, didodecyl phthalate, dimethyl terephthalate, diethylterephthalate, dipropyl terephthalate, dibutyl terephthalate, dipentylterephthalate, dihexyl terephthalate, diheptyl terephthalate, dioctylterephthalate, dinonyl terephthalate, didecyl terephthalate, didodecylterephthalate, propylene carbonate, and γ-butyrolactone; thehydrocarbons are at least one member selected from the group consistingof hexane, cyclohexane, octane, isooctane, benzene, and toluene; thehalogen compounds are at least one member selected from the groupconsisting of chloroform, o-dichlorobenzene, perfluorohexane, andperfluoromethylcyclohexane; the fluorinated alcohols are at least onemember selected from the group consisting of trifluoroethanol,pentafluoropropanol, and 2,2,3,3-tetrafluoropropanol; the phosphateesters are at least one member selected from the group consisting ofdimethyl phosphate, dibutyl phosphate, diphenyl phosphate, dibenzylphosphate, trimethyl phosphate, triethyl phosphate, tripropyl phosphate,tributyl phosphate, and triphenyl phosphate; and the nitrogen-containingcompounds are at least one member selected from the group consisting oftetramethylurea and N-methyl-2-pyrrolidone.
 15. A method of removingresist, comprising treating an object having resist on the surface of alow-k film or on an antireflection coating (BARC) over a low-k film, bythe use of the removing solution of claim 1 under temperature and timeconditions such that the resist can be removed without substantiallydamaging the low-k film.
 16. A method according to claim 15, comprisingan ashing treatment for the resist without substantially damaging thelow-k film, before treating the object using the removing solution. 17.A method according to claim 15, wherein the low-k film is substantiallyundamaged because the low-k film is substantially unetched and/or thedielectric constant of the low-k film is substantially unchanged beforeand after the treatment.
 18. A method according to claim 15, comprisingtreating the object while performing ultrasonic cleaning.
 19. Aresist-removed object that can be obtained according to the method ofclaim
 15. 20. A cleaning solution for a via hole or a capacitorcomprising hydrogen fluoride (HF) and at least one member selected fromthe group consisting of organic acids and organic solvents.
 21. Acleaning solution according to claim 20, further comprising at least onemember selected from the group consisting of ammonia and amines.
 22. Aremoving solution according to claim 20, wherein the solution is usedfor ultrasonic cleaning.
 23. A cleaning solution according to claim 20,whereby a TiN film can be etched to a depth of at least 0.01 Å.
 24. Acleaning solution according to claim 20, further comprising water,wherein the weight ratio of HF/organic acid/water is in the range of0.01 to 5 mass %/49 to 99.9 mass %/0 to 50 mass %; and the organic acidis at least one member selected from the group consisting ofmonocarboxylic acids, sulfonic acids, and polycarboxylic acids.
 25. Acleaning solution according to claim 24, wherein the monocarboxylicacids are at least one member selected from the group consisting ofacetic acid, propionic acid, butyric acid, isobutyric acid, valericacid, caproic acid, caprylic acid, monochloroacetic acid, dichloroaceticacid, trichloroacetic acid, monofluoroacetic acid, difluoroacetic acid,trifluoroacetic acid, α-chlorobutyric acid, β-chlorobutyric acid,γ-chlorobutyric acid, lactic acid, glycolic acid, pyruvic acid,glyoxalic acid, methacrylic acid, and acrylic acid; the sulfonic acidsare at least one member selected from the group consisting ofmethanesulfonic acid, benzenesulfonic acid, trifluoromethanesulfonicacid, and toluenesulfonic acid; and the polycarboxylic acids are atleast one member selected from the group consisting of oxalic acid,succinic acid, adipic acid, tartaric acid, and citric acid.
 26. Acleaning solution according to claim 20, further comprising water,wherein the weight ratio of HF/organic solvent/water is in the range of0.01 to 10 mass %/49 to 99.9 mass %/0 to 50 mass %; and the organicsolvent is at least one member selected from the group consisting ofmonohydric alcohols, polyols, ketones, amides, nitriles, aldehydes,alkylene glycol monoalkyl ethers, ethers, esters, hydrocarbons, halogencompounds, fluorinated alcohols, phosphate esters, andnitrogen-containing compounds.
 27. A cleaning solution according toclaim 21, wherein the weight ratio of HF/said at least one memberselected from the group consisting of ammonia and amines/organicsolvent/water is in the range of 0.01 to 10 mass %/0.01 to 30 mass %/49to 99.9 mass %/0 to 50 mass %; and the organic solvent is at least onemember selected from the group consisting of monohydric alcohols,polyols, ketones, amides, nitriles, aldehydes, alkylene glycol monoalkylethers, ethers, esters, hydrocarbons, halogen compounds, fluorinatedalcohols, phosphate esters, and nitrogen-containing compounds.
 28. Acleaning solution according to claim 26, wherein the monohydric alcoholsare at least one member selected from the group consisting of methanol,ethanol, isopropanol (IPA), 1-propanol, 1-butanol, 2-butanol, t-butanol,2-methyl-1-propanol, 1-pentanol, 1-hexanol, 1-heptanol, 4-heptanol,1-octanol, 1-nonyl alcohol, 1-decanol, 1-dodecanol, lauryl alcohol, andcyclohexanol; the polyols are at least one member selected from thegroup consisting of ethylene glycol, diethylene glycol, 1,2-propanediol,propylene glycol, 2,3-butanediol, and glycerin; the ketones are at leastone member selected from the group consisting of acetone, acetylacetone,methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, diethylketone, and diisobutyl ketone; the amides are at least one memberselected from the group consisting of N-methylformamide,N,N-dimethylformamide, N-methylacetamide, and N,N-dimethylacetamide; thenitriles are at least one member selected from the group consisting ofacetonitrile, propionitrile, butyronitrile, isobutyronitrile, andbenzonitrile; the aldehydes are at least one member selected from thegroup consisting of formaldehyde, acetaldehyde, and propionaldehyde; thealkylene glycol monoalkyl ethers are at least one member selected fromthe group consisting of ethylene glycol monomethyl ether and ethyleneglycol monoethyl ether; the ethers are at least one member selected fromthe group consisting of tetrahydrofuran, dioxane, diisopropyl ether,dibutyl ether, tetrahydropyran, anisole, 1,2-dimethoxyethane, anddiethylene glycol dimethyl ether; the esters are at least one memberselected from the group consisting of methyl acetate, ethyl acetate,propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate,pentyl acetate, hexyl acetate, methyl propionate, ethyl propionate,propyl propionate, isopropyl propionate, butyl propionate, isobutylpropionate, pentyl propionate, hexyl propionate, methyl butyrate, ethylbutyrate, propyl butyrate, isopropyl butyrate, butyl butyrate, isobutylbutyrate, pentyl butyrate, hexyl butyrate, methyl isobutyrate, ethylisobutyrate, propyl isobutyrate, isopropyl isobutyrate, butylisobutyrate, isobutyl isobutyrate, pentyl isobutyrate, hexylisobutyrate, methyl valerate, ethyl valerate, propyl valerate, isopropylvalerate, butyl valerate, isobutyl valerate, pentyl valerate, hexylvalerate, methyl isovalerate, ethyl isovalerate, propyl isovalerate,isopropyl isovalerate, butyl isovalerate, isobutyl isovalerate, pentylisovalerate, hexyl isovalerate, methyl caproate, ethyl caproate, propylcaproate, isopropyl caproate, butyl caproate, isobutyl caproate, pentylcaproate, hexyl caproate, methyl caprylate, ethyl caprylate, propylcaprylate, isopropyl caprylate, butyl caprylate, isobutyl caprylate,pentyl caprylate, hexyl caprylate, methyl octanoate, ethyl octanoate,propyl octanoate, isopropyl octanoate, butyl octanoate, isobutyloctanoate, pentyl octanoate, hexyl octanoate, methyl nonanoate, ethylnonanoate, propyl nonanoate, isopropyl nonanoate, butyl nonanoate,isobutyl nonanoate, pentyl nonanoate, hexyl nonanoate, methyl decanoate,ethyl decanoate, propyl decanoate, isopropyl decanoate, butyl decanoate,isobutyl decanoate, pentyl decanoate, hexyl decanoate, methyldodecanoate, ethyl dodecanoate, propyl dodecanoate, isopropyldodecanoate, butyl dodecanoate, isobutyl dodecanoate, pentyldodecanoate, hexyl dodecanoate, methyl laurate, ethyl laurate, propyllaurate, isopropyl laurate, butyl laurate, isobutyl laurate, pentyllaurate, hexyl laurate, methyl acrylate, ethyl acrylate, propylacrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, pentylacrylate, hexyl acrylate, monomethyl oxalate, dimethyl oxalate,monoethyl oxalate, diethyl oxalate, monopropyl oxalate, dipropyloxalate, monobutyl oxalate, dibutyl oxalate, monomethyl succinate,dimethyl succinate, monoethyl succinate, diethyl succinate, monopropylsuccinate, dipropyl succinate, monobutyl succinate, dibutyl succinate,monomethyl adipate, dimethyl adipate, monoethyl adipate, diethyladipate, monopropyl adipate, dipropyl adipate, monobutyl adipate,dibutyl adipate, monomethyl tartrate, dimethyl tartrate, monoethyltartrate, diethyl tartrate, monopropyl tartrate, dipropyl tartrate,monobutyl tartrate, dibutyl tartrate, monomethyl citrate, dimethylcitrate, monoethyl citrate, diethyl citrate, monopropyl citrate,dipropyl citrate, monobutyl citrate, dibutyl citrate, dimethylphthalate, diethyl phthalate, dipropyl phthalate, dibutyl phthalate,dipentyl phthalate, dihexyl phthalate, diheptyl phthalate, dioctylphthalate, dinonyl phthalate, didecyl phthalate, didodecyl phthalate,dimethyl, terephthalate, diethyl terephthalate, dipropyl terephthalate,dibutyl terephthalate, dipentyl terephthalate, dihexyl terephthalate,diheptyl terephthalate, dioctyl terephthalate, dinonyl terephthalate,didecyl terephthalate, didodecyl terephthalate, propylene carbonate, andγ-butyrolactone; the hydrocarbons are at least one member selected fromthe group consisting of hexane, cyclohexane, octane, isooctane, benzene,and toluene; the halogen compounds are at least one member selected fromthe group consisting of chloroform, o-dichlorobenzene, perfluorohexane,and perfluoromethylcyclohexane; the fluorinated alcohols are at leastone member selected from the group consisting of trifluoroethanol,pentafluoropropanol, and 2,2,3,3-tetrafluoropropanol; the phosphateesters are at least one member selected from the group consisting ofdimethyl phosphate, dibutyl phosphate, diphenyl phosphate, dibenzylphosphate, trimethyl phosphate, triethyl phosphate, tripropyl phosphate,tributyl phosphate, and triphenyl phosphate; and the nitrogen-containingcompounds are at least one member selected from the group consisting oftetramethylurea and N-methyl-2-pyrrolidone.
 29. A method of cleaning avia hole, comprising cleaning an object that has a via hole, with atleast one member selected from the group consisting of titaniumcompounds and polymers adhering to at least one member selected from thegroup consisting of the sidewall and the bottom of the via hole, by theuse of the cleaning solution of claim
 20. 30. A method according toclaim 29, comprising treating the object while performing ultrasoniccleaning.
 31. A cleaned object that can be obtained according to themethod of claim
 29. 32. A method of cleaning a capacitor, comprisingcleaning an object that has a metal capacitor upper electrode or lowerelectrode, with at least one member selected from the group consistingof resist residue, polymers, and titanium compounds adhering to at leastone member selected from the group consisting of the sidewall, thebottom, and the surface of the electrode, by the use of the cleaningsolution of claim
 20. 33. A method according to claim 32, comprisingtreating the object while performing ultrasonic cleaning.
 34. A cleanedobject that can be obtained according to the method of claim
 32. 35. Aresist-removing solution according to claim 1, wherein the solutionetches, in a treatment time of 0.1 to 120 minutes, (1) an insulatingfilm barrier to a depth of 1 to 200 Å, (2) low-k film to a depth of 1 to200 Å, and (3) Cu at an etching rate of no more than 10 Å/min; and thesolution removes resist, antireflection coating, filling material, andetching residue including these, after dry etching in the formation ofdamascene and dual damascene structures for Cu/low-k multilevelinterconnection.
 36. A removing solution according to claim 35, whereinthe insulating film barrier and the low-k film are Si-containingcompounds such as SiN, SiC, SiCN, SiOC, and SiO₂.
 37. A removingsolution according to claim 35, wherein the solution removes residueresulting from etching with a nitrogen-containing etching gas,regardless of whether plasma ashing is conducted or not.
 38. A removingsolution according to claim 35, wherein the solution removes residueafter ashing with a nitrogen-containing gas.
 39. A removing solutionaccording to claim 35, wherein one or more inert gases are dissolved inthe solution such that the oxygen partial pressure in the solution isbelow the oxygen partial pressure in air-saturated solution.
 40. Aremoving solution according to claim 35, comprising (i) HF, (ii) aprotogenic solvent, and (iii) at least one organic compound selectedfrom the group consisting of polar protophilic solvents and polarprotophobic solvents having a donor number of no more than 24, andneutral solvents; wherein the weight ratio of (i) HF (hydrogenfluoride)/(ii) protogenic solvent/(iii) said at least one organiccompound selected from the group consisting of polar protophilicsolvents and polar protophobic solvents having a donor number of no morethan 24, and neutral solvents is in the range of (i) 0.05 to 5 mass%/(ii) 1 to 98.95 mass %/(iii) 1 to 98.95 mass %.
 41. A removingsolution according to claim 35, comprising (i) HF, (ii) a protogenicsolvent, and (iii) at least one organic compound selected from the groupconsisting of polar protophilic solvents and polar protophobic solventshaving a donor number of no more than 24, and neutral solvents, andfurther comprising (iv) water; wherein the weight ratio of (i) HF(hydrogen fluoride)/(ii) protogenic solvent/(iii) said at least oneorganic compound selected from the group consisting of polar protophilicsolvents and polar protophobic solvents having a donor number of no morethan 24, and neutral solvents/(iv) water is in the range of (i) 0.05 to5 mass %/(ii) 1 to 98.93 mass %/(iii) 1 to 98.93 mass %/(iv) 0.02 to 90mass %.
 42. A removing solution according to claim 35, comprising (i)HF, (ii) a protogenic solvent, (iii) at least one organic compoundselected from the group consisting of polar protophilic solvents andpolar protophobic solvents having a donor number of no more than 24, andneutral solvents, and (iv) water, and further comprising at least onemember selected from the group consisting of (v) acids, (vi) polarprotophilic solvents having a donor number of at least 25, and (vii)fluorine-containing organic compounds; wherein the weight ratio of (i)HF/(ii) protogenic solvent/(iii) said at least one organic compoundselected from the group consisting of polar protophilic solvents andpolar protophobic solvents having a donor number of no more than 24, andneutral solvents/(iv) water/(v) acid/(vi) polar protophilic solventhaving a donor number of at least 25/(vii) fluorine-containing organiccompound is in the range of (i) 0.05 to 5 mass %/(ii) 1 to 98.83 mass%/(iii) 1 to 98.83 mass %/(iv) 0.02 to 90 mass %/(v) 0 to 10 mass %/(vi)0 to 50 mass %/(vii) 0 to 70 mass %, with the total amount of acid,polar protophilic solvent having a donor number of at least 25, andfluorine-containing organic compound being 0.1 to 74.93 mass %.
 43. Aremoving solution according to claim 35, comprising (i) HF, (ii) aprotogenic solvent, (iii) at least one organic compound selected fromthe group consisting of polar protophilic solvents and polar protophobicsolvents having a donor number of no more than 24, and neutral solvents,(iv) water, and at least one member selected from the group consistingof (v) acids, (vi) polar protophilic solvents having a donor number ofat least 25, and (vii) fluorine-containing organic compounds, andfurther comprising ammonia and/or amine(s); wherein the weight ratio of(i) HF/(ii) protogenic solvent/(iii) said at least one organic compoundselected from the group consisting of polar protophilic solvents andpolar protophobic solvents having a donor number of no more than 24, andneutral solvents/(iv) water/(v) acid/(vi) polar protophilic solventhaving a donor number of at least 25/(vii) fluorine-containing organiccompound/(viii) ammonia and/or amine is in the range of (i) 0.05 to 5mass %/(ii) 1 to 98.73 mass %/(iii) 1 to 98.73 mass %/(iv) 0.02 to 90mass %/(v) 0 to 10 mass %/(vi) 0 to 50 mass %/(vii) 0 to 70 mass%/(viii) 0.05 to 10 mass %, with the total amount of acid, polarprotophilic solvent having a donor number of at least 25, andfluorine-containing organic compound being 0.1 to 74.83 mass %.
 44. Aremoving solution according to claim 35, comprising (i) HF, (ii) atleast one organic compound selected from the group consisting of polarprotophilic solvents and polar protophobic solvents having a donornumber of no more than 24, neutral solvents, and protogenic solvents,and (iii) water; wherein the weight ratio of (i) HF (hydrogenfluoride)/(ii) said at least one organic compound selected from thegroup consisting of polar protophilic solvents and polar protophobicsolvents having a donor number of no more than 24, neutral solvents, andprotogenic solvents/(iii) water is in the range of (i) 0.05 to 5 mass%/(ii) 85 to 99.93 mass %/(iii) 0.02 to 10 mass %.
 45. A removingsolution according to claim 35, comprising (i) HF, (ii) at least oneorganic compound selected from the group consisting of polar protophilicsolvents and polar protophobic solvents having a donor number of no morethan 24, neutral solvents, and protogenic solvents, and (iii) water, andfurther comprising at least one member selected from the groupconsisting of acids, polar protophilic solvents having a donor number ofat least 25, and fluorine-containing organic compounds; wherein theweight ratio of (i) HF/(ii) said at least one organic compound selectedfrom the group consisting of polar protophilic solvents and polarprotophobic solvents having a donor number of no more than 24, neutralsolvents, and protogenic solvents/(iii) water/(iv) acid/(v) polarprotophilic solvent having a donor number of at least 25/(vi)fluorine-containing organic compound is in the range of (i) 0.05 to 5mass %/(ii) 25 to 99.83 mass %/(iii) 0.02 to 10 mass %/(iv) 0 to 10 mass%/(v) 0 to 50 mass %/(vi) 0 to 70 mass %, with the total amount of acid,polar protophilic solvent having a donor number of at least 25, andfluorine-containing organic compound being 0.1 to 74.93 mass %.
 46. Aremoving solution according to claim 35, comprising (i) HF, (ii) atleast one organic compound selected from the group consisting of polarprotophilic solvents and polar protophobic solvents having a donornumber of no more than 24, neutral solvents, and protogenic solvents,(iii) water, and at least one member selected from the group consistingof (iv) acids, (v) polar protophilic solvents having a donor number ofat least 25, and (vi) fluorine-containing organic compounds, and furthercomprising (vii) ammonia and/or amine(s); wherein the weight ratio of(i) HF/(ii) said at least one organic compound selected from the groupconsisting of polar protophilic solvents and polar protophobic solventshaving a donor number of no more than 24, neutral solvents, andprotogenic solvents/(iii) water/(iv) acid/(v) polar protophilic solventhaving a donor number of at least 25/(vi) fluorine-containing organiccompound/(viii) ammonia and/or amine is in the range of (i) 0.05 to 5mass %/(ii) 25 to 99.78 mass %/(iii) 0.02 to 10 mass %/(iv) 0 to 10 mass%/(v) 0 to 10 mass %/(vi) 0 to 70 mass %/(vii) 0.05 to 10 mass %, withthe total amount of said at least one member selected from the groupconsisting of acids, polar protophilic solvents having a donor number ofat least 25, and fluorine-containing organic compounds being 0.1 to74.88 mass %.
 47. A removing solution according to claim 40, wherein theneutral solvents are alcohols; the protogenic solvents aremonocarboxylic acids, polycarboxylic acids, and sulfonic acids; and thepolar aprotoic solvents having a donor number of no more than 24 areesters and ethers; and the polar protophilic solvents having a donornumber of at least 25 are esters, ethers, ketones, and acid anhydrides.48. A removing solution according to claim 47, wherein (I) as theneutral solvents, the alcohols are methyl alcohol, ethyl alcohol,propanol, isopropanol, t-butanol, allyl alcohol, and ethylene glycol;(II) as the protogenic solvents, the monocarboxylic acids are formicacid, acetic acid, propionic acid, butyric acid, isobutyric acid,monochloroacetic acid, dichloroacetic acid, trichloroacetic acid,monofluoroacetic acid, difluoroacetic acid, trifluoroacetic acid,α-chlorobutyric acid, β-chlorobutyric acid, γ-chlorobutyric acid, lacticacid, glycolic acid, pyruvic acid, glyoxalic acid, methacrylic acid, andacrylic acid; the polycarboxylic acids are oxalic acid, succinic acid,adipic acid, and citric acid; acid the sulfonic acids aremethanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, andtrifluoromethanesulfonic acid; (III) as the polar protophilic solventshaving a donor number of no more than 24, the esters are tributylphosphate and trimethyl phosphate; the ethers are 1,2-dimethoxyethane,tetrahydrofuran, diethyl ether, ethylene glycol monomethyl ether,ethylene glycol monoethyl ether, dimethoxymethane, dimethoxypropane,diethoxymethane, and 1,1-dimethoxyethane; (IV) as the polar protophobicsolvents, the esters are methyl acetate, ethyl acetate, butyl acetate,propylene carbonate, ethylene carbonate, ethylene sulfite, and lactone;the ethers are dioxane, trioxane, and diglyme; the ketones are acetone;and the acid anhydrides are acetic anhydride.
 49. A removing solutionaccording to claim 42, wherein the acids are at least one memberselected from the group consisting of hydrogen chloride, hydrogenbromide, hydrogen iodide, aqueous solutions thereof, sulfuric acid,nitric acid, phosphoric acid, and carboxylic acid.
 50. A removingsolution according to claim 42, wherein the fluorine-containing organiccompounds are fluorine-containing ethers such as CHF₂CF₂OCH₂CF₃ andCHF₂CF₂OCH₄; and hydrochlorofluorocarbons (HCFCs) such as and CH₃CCl₂Fand CClF₂CF₂CHClF.
 51. A removing solution according to claim 42,wherein the polar protophilic solvents having a donor number of at least25 are at least one member selected from the group consisting of amidessuch as dimethylformamide, dimethylacetamide, hexamethylphosphorictriamide, N-methyl-2-pyrrolidone, 1,1,3,3-tetramethylurea,N-methylpropionamide, and dimethyl imidazolidinone; and sulfur compoundssuch as dimethyl sulfoxide, sulfolane, dimethylthioformamide, andN-methylthiopyrrolidone.
 52. A removing solution according to claim 40,wherein the solution comprises a carboxylic acid as a protogenicsolvent; and at least one member selected from the group consisting ofalcohols as neutral solvents, and esters and ethers as polar aproticsolvents having a donor number of no more than
 24. 53. A removingsolution according to claim 52, wherein the carboxylic acid is aceticacid.
 54. A removing solution according to claim 47, wherein thesolution comprises an alcohol as a neutral solvent; and at least onemember selected from the group consisting of esters and ethers as polaraprotic solvents having a donor number of no more than
 24. 55. Aremoving solution according to claim 47, wherein the alcohols are atleast one member selected from the group consisting of propanol,isopropanol, t-butanol, allyl alcohol, and ethylene glycol.
 56. Aremoving solution according to claim 40, wherein the solution comprisesat least one member selected from the group consisting of esters andethers as polar aprotic solvents having a donor number of no more than24.
 57. A removing solution according to claim 40, wherein the estersare at least one member selected from the group consisting of methylacetate, ethyl acetate, butyl acetate, propylene carbonate, and ethylenecarbonate; and the ethers are at least one member selected from thegroup consisting of 1,2-dimethoxyethane, tetrahydrofuran, dioxane,trioxane, diglyme, ethylene glycol monomethyl ether, ethylene glycoldiethyl ether, diethylene glycol methyl ethyl ether, tetraethyleneglycol dimethyl ether, polyethylene glycol dimethyl ether, ethyleneglycol monoallyl ether, diethylene glycol monobutyl ether, ethyleneglycol butyl ether, triethylene glycol monobutyl ether, diethyleneglycol diethyl ether, diethylene glycol dimethyl ether, triethyleneglycol dimethyl ether, diethylene glycol monoisobutyl ether, ethyleneglycol monoisobutyl ether, ethylene glycol monoisopropyl ether,diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether,propylene glycol monomethyl ether, tripropylene glycol monomethyl ether,ethylene glycol monoethyl ether, polyethylene glycol monomethyl ether,triethylene glycol monomethyl ether, propylene glycol monopropyl ether,and ethylene glycol methyl ethyl ether.
 58. A removing solutionaccording to claim 44, comprising HF, acetic acid, and water; whereinthe weight ratio of HF/acetic acid/water is in the range of 0.05 to 5mass %/85 to 99.93 mass %/0.02 to 10 mass %.
 59. A removing solutionaccording to claim 44, comprising HF, isopropanol, and water; whereinthe weight ratio of HF/isopropanol/water is in the range of 1 to 7 mass%/88 to 98.5 mass %/0.5 to 5 mass %.
 60. A removing solution accordingto claim 44, comprising HF, acetic acid, isopropanol, and water; whereinthe weight ratio of HF/acetic acid/isopropanol/water is in the range of0.05 to 6 mass %/1 to 98.93 mass %/1 to 98.85 mass %/0.02 to 12 mass %.61. A removing solution according to claim 44, comprising HF,1,2-dimethoxyethane, and water; wherein the weight ratio ofHF/1,2-dimethoxyethane/water is in the range of 0.50 to 5 mass %/85.00to 99.3 mass %/0.02 to 10 mass %.
 62. A removing solution according toclaim 44, comprising HF; at least one member selected from the groupconsisting of methyl acetate, ethyl acetate, and butyl acetate; andwater; wherein the weight ratio of HF/said at least one member selectedfrom the group consisting of methyl acetate, ethyl acetate, and butylacetate/water is in the range of 0.50 to 5 mass %/85.00 to 99.30 mass%/0.02 to 10 mass %.
 63. A removing solution according to claim 44,comprising HF, 1,4-dioxane, and water; wherein the weight ratio ofHF/1,4-dioxane/water is in the range of 0.50 to 5 mass %/85.00 to 99.3mass %/0.2 to 10 mass %.
 64. A removing solution according to claim 44,comprising HF; 1,4-dioxane and at least one member selected from thegroup consisting of acetic anhydride and acetic acid; and water; whereinthe weight ratio of HF/1,4-dioxane and said at least one member selectedfrom the group consisting of acetic anhydride and acetic acid/water isin the range of 0.50 to 6 mass %/82.00 to 99.30 mass %/0.2 to 12 mass %.65. A removing solution according to claim 44, comprising HF; at leastone member selected from the group consisting of ethylene glycolmonomethyl ether, ethylene glycol diethyl ether, diethylene glycolmethyl ethyl ether, tetraethylene glycol dimethyl ether, polyethyleneglycol dimethyl ether, ethylene glycol monoallyl ether, diethyleneglycol monobutyl ether, ethylene glycol butyl ether, triethylene glycolmonobutyl ether, diethylene glycol diethyl ether, diethylene glycoldimethyl ether, triethylene glycol dimethyl ether, diethylene glycolmonoisobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycolmonoisopropyl ether, diethylene glycol monomethyl ether, dipropyleneglycol monomethyl ether, propylene glycol monomethyl ether, tripropyleneglycol monomethyl ether, ethylene glycol monoethyl ether, polyethyleneglycol monomethyl ether, triethylene glycol monomethyl ether, propyleneglycol monopropyl ether, and ethylene glycol methyl ethyl ether; andwater; wherein the weight ratio of HF/said at least one member selectedfrom the group consisting of ethylene glycol monomethyl ether, ethyleneglycol diethyl ether, diethylene glycol methyl ethyl ether,tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether,ethylene glycol monoallyl ether, diethylene glycol monobutyl ether,ethylene glycol butyl ether, triethylene glycol monobutyl ether,diethylene glycol diethyl ether, diethylene glycol dimethyl ether,triethylene glycol dimethyl ether, diethylene glycol monoisobutyl ether,ethylene glycol monoisobutyl ether, ethylene glycol monoisopropyl ether,diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether,propylene glycol monomethyl ether, tripropylene glycol monomethyl ether,ethylene glycol monoethyl ether, polyethylene glycol monomethyl ether,triethylene glycol monomethyl ether, propylene glycol monopropyl ether,and ethylene glycol methyl ethyl ether/water is in the range of 0.50 to5 mass %/85.00 to 99.30 mass %/0.20 to 10 mass %.
 66. A removingsolution according to claim 35, comprising HF, methanesulfonic acid, andwater; wherein the weight ratio of HF/methanesulfonic acid/water is inthe range of more than 0 and not more than 5 mass %/at least 45 and lessthan 100 mass %/more than 0 and not more than 50 mass %.
 67. A removingmethod comprising removing etching residue while leaving low-k film thathas been damaged by a plasma process, by the use of the removingsolution of claim
 1. 68. A method according to claim 15, comprisingperforming a removal treatment under an atmosphere (substantially ininert gas) wherein one or more inert gases are mixed such that theatmosphere has an oxygen partial pressure below the oxygen partialpressure in air.
 69. A rinse treatment method for removing a removingsolution from an object treated by the method of claim 15, comprisingperforming a rinse treatment using water wherein one or more inert gasesare dissolved such that the oxygen partial pressure in the water isbelow the oxygen partial pressure in air-saturated solution, under anatmosphere (substantially in inert gas) wherein one or more inert gasesare mixed such that the atmosphere has an oxygen partial pressure belowthe oxygen partial pressure in air.
 70. A removal-treated object thatcan be obtained by treatment according to the removing method of claim67, and the rinse treatment method of claim
 69. 71. A cleaning solutionfor a via hole or a capacitor according to claim 20, wherein theremoving solution of claim 35 is used to clean the via hole or thecapacitor.
 72. A method of cleaning a via hole according to claim 29,comprising using the cleaning solution for a via hole or a capacitor ofclaim
 71. 73. A cleaned object that can be obtained by cleaningtreatment using the cleaning solution for a via hole or a capacitor ofclaim 71.